drm/amd/pm/powerplay/hwmgr/ppevvmath: Clean up errors in ppevvmath.h

Fix the following errors reported by checkpatch:

ERROR: return is not a function, parentheses are not required
ERROR: space required after that ',' (ctx:VxV)
ERROR: space required before the open parenthesis '('
ERROR: need consistent spacing around '-' (ctx:WxV)

Signed-off-by: Ran Sun <sunran001@208suo.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/amd/pm/powerplay/hwmgr/ppevvmath: Place variable declaration under same clause as its use

Fixes the following W=1 kernel build warning(s):

drivers/gpu/drm/amd/amdgpu/../pm/powerplay/hwmgr/ppevvmath.h: In function ‘fMultiply’:
drivers/gpu/drm/amd/amdgpu/../pm/powerplay/hwmgr/ppevvmath.h:336:22: warning: variable ‘Y_LessThanOne’ set but not used [-Wunused-but-set-variable]
drivers/gpu/drm/amd/amdgpu/../pm/powerplay/hwmgr/ppevvmath.h:336:7: warning: variable ‘X_LessThanOne’ set but not used [-Wunused-but-set-variable]

Cc: Evan Quan <evan.quan@amd.com>
Cc: Alex Deucher <alexander.deucher@amd.com>
Cc: "Christian König" <christian.koenig@amd.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Cc: amd-gfx@lists.freedesktop.org
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drm/amd/pm: optimize the power related source code layout

The target is to provide a clear entry point(for power routines).
Also this can help to maintain a clear view about the frameworks
used on different ASICs. Hopefully all these can make power part
more friendly to play with.

Signed-off-by: Evan Quan <evan.quan@amd.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>