drm: remove I2C_CLASS_DDC support

After removal of the legacy EEPROM driver and I2C_CLASS_DDC support in
olpc_dcon there's no i2c client driver left supporting I2C_CLASS_DDC.
Class-based device auto-detection is a legacy mechanism and shouldn't
be used in new code. So we can remove this class completely now.

Acked-by: Alex Deucher <alexander.deucher@amd.com>
Acked-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Acked-by: Harry Wentland <harry.wentland@amd.com>
Acked-by: Heiko Stuebner <heiko@sntech.de>
Acked-by: Jani Nikula <jani.nikula@intel.com>
Acked-by: Jernej Skrabec <jernej.skrabec@gmail.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Reviewed-by: AngeloGioacchino Del Regno <angelogioacchino.delregno@collabora.com>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Wolfram Sang <wsa@kernel.org>

drm/ast: Rename AST_IO_CRTC_PORT to AST_IO_VGACRI

Rename AST_IO_CRTC_PORT to AST_IO_VGACRI to align naming
in the driver with documentation. No functional changes.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Jocelyn Falempe <jfalempe@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231017083653.10063-10-tzimmermann@suse.de

drm/ast: Rename to_ast_private() to to_ast_device()

The helper to_ast_private() now upcasts to struct ast_device. Rename
it accordingly. No functional changes.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230221155745.27484-5-tzimmermann@suse.de

drm/ast: Rename struct ast_private to struct ast_device

The data structure struct ast_private represents an AST device. Its
name comes from the time when it was allocated and stored separately
in struct drm_device.dev_private. The DRM device is now embedded, so
rename struct ast_private to struct ast_device.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230221155745.27484-4-tzimmermann@suse.de

drm/ast: Move I2C code into separate source file

Move I2C code into its own source file. Makes the mode-setting
code a little less convoluted.

v3:
* fix SPDX tag to say 'SPDX-License-Identifier'

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Acked-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20211206091125.29501-4-tzimmermann@suse.de