drm/amd/display: Clean FPGA code in dc

[Why]
Drop dead code for Linux.

[How]
Remove all IS_FPGA_MAXIMUS_DC and IS_DIAG_DC

Reviewed-by: Ariel Bernstein <eric.bernstein@amd.com>
Acked-by: Tom Chung <chiahsuan.chung@amd.com>
Signed-off-by: Qingqing Zhuo <qingqing.zhuo@amd.com>
Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/amd/display: remove unused variables dispclk_delay_subtotal and dout

clang with W=1 reports
drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn314/display_rq_dlg_calc_314.c:1003:15:
error: variable 'dispclk_delay_subtotal' set but not used [-Werror,-Wunused-but-set-variable]
unsigned int dispclk_delay_subtotal;
^
This variable is not used, so remove it.
Which made dout unused, so also remove.

Signed-off-by: Tom Rix <trix@redhat.com>
Signed-off-by: Hamza Mahfooz <hamza.mahfooz@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/amd/display: update extended blank for dcn314 onwards

[Why]
Flickering and underflow was observed when testing extended
blank on dcn314.

[What]
Vstartup is contrainted by vblank_nom, so adjusting it to include
non-adjusted vtotal in its calculation during freesync video
means that Vstartup is not changed when vtotal changes.
This fixed the flickering + underflow.

dc_extended_blank_supported function was removed
because extended blank is only relevant to when
zstate is supported. The increased vtotal during
freesync can be passed to dml regardless of whether
extended blank is supported or not, so this function is
not needed.

Updates were made recently in dml to the calculation of
min_dst_y_next_start. Dml input for dcn314 will now
always use the newer calculation for min_dst_y_next_start.
Dml input for older dcn versions remains untouched.

The variable optimized_min_dst_y_next_start
is replaced everywhere with min_dst_y_next_start,
and the updated dml allows min_dst_y_next_start to
increase to an optimized value during freesync video,
then return to default when freesync is disengaged.

Also removed registry key for controlling
extended blank feature.

Tested-by: Daniel Wheeler <daniel.wheeler@amd.com>
Reviewed-by: Nicholas Kazlauskas <Nicholas.Kazlauskas@amd.com>
Acked-by: Rodrigo Siqueira <Rodrigo.Siqueira@amd.com>
Signed-off-by: Gabe Teeger <gabe.teeger@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/amd/display: Remove unused variable 'scl_enable'

Compiling AMD GPU drivers displays a warning:

drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn314/display_rq_dlg_calc_314.c: In function ‘dml_rq_dlg_get_dlg_params’:
drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn314/display_rq_dlg_calc_314.c:991:14: warning: variable ‘scl_enable’ set but not used [-Wunused-but-set-variable]

Get rid of it by removing the variable 'scl_enable'.

Signed-off-by: Caio Novais <caionovais@usp.br>
Signed-off-by: Hamza Mahfooz <hamza.mahfooz@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/amd/display: Remove the unused variable dppclk_delay_subtotal

Variable dppclk_delay_subtotal is not effectively used, so delete it.

drivers/gpu/drm/amd/amdgpu/../display/dc/dml/dcn314/display_rq_dlg_calc_314.c:1004:15: warning: variable 'dppclk_delay_subtotal' set but not used.

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Link: https://bugzilla.openanolis.cn/show_bug.cgi?id=4584
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: Hamza Mahfooz <hamza.mahfooz@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/amd/display: Remove duplicate/repeating expression

Remove duplicate or repeating expressions in the if condition
evaluation. Issue identified using doubletest.cocci Coccinelle semantic
patch.

Reviewed-by: Harry Wentland <harry.wentland@amd.com>
Signed-off-by: Deepak R Varma <drv@mailo.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/amd/display: Add DCN314 DML calculation support

Display mode library for DCN 3.1.4

v2: squash in checkpatch fix (Alex)

Signed-off-by: Roman Li <roman.li@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>