drm/vkms: Add support for RGB888 formats

Add the support for:
- RGB888
- BGR888

Reviewed-by: Maíra Canal <mcanal@igalia.com>
Acked-by: Daniel Stone <daniels@collabora.com>
Link: https://lore.kernel.org/r/20250703-b4-new-color-formats-v7-5-15fd8fd2e15c@bootlin.com
Signed-off-by: Louis Chauvet <louis.chauvet@bootlin.com>

Author: Fomys

drivers/gpu/drm/vkms/vkms_formats.c

@@ -455,6 +455,9 @@ READ_LINE_ARGB8888(ABGR8888_read_line, px, px[3], px[0], px[1], px[2])
 READ_LINE_ARGB8888(RGBA8888_read_line, px, px[0], px[3], px[2], px[1])
 READ_LINE_ARGB8888(BGRA8888_read_line, px, px[0], px[1], px[2], px[3])
 
+READ_LINE_ARGB8888(RGB888_read_line, px, 0xFF, px[2], px[1], px[0])
+READ_LINE_ARGB8888(BGR888_read_line, px, 0xFF, px[0], px[1], px[2])
+
 READ_LINE_le16161616(ARGB16161616_read_line, px, px[3], px[2], px[1], px[0])
 READ_LINE_le16161616(ABGR16161616_read_line, px, px[3], px[0], px[1], px[2])
 READ_LINE_le16161616(XRGB16161616_read_line, px, cpu_to_le16(0xFFFF), px[2], px[1], px[0])
@@ -676,6 +679,10 @@ pixel_read_line_t get_pixel_read_line_function(u32 format)
 		return &XRGB8888_read_line;
 	case DRM_FORMAT_XBGR8888:
 		return &XBGR8888_read_line;
+	case DRM_FORMAT_RGB888:
+		return &RGB888_read_line;
+	case DRM_FORMAT_BGR888:
+		return &BGR888_read_line;
 	case DRM_FORMAT_ARGB16161616:
 		return &ARGB16161616_read_line;
 	case DRM_FORMAT_ABGR16161616:

drivers/gpu/drm/vkms/vkms_plane.c

@@ -19,6 +19,8 @@ static const u32 vkms_formats[] = {
 	DRM_FORMAT_RGBA8888,
 	DRM_FORMAT_XRGB8888,
 	DRM_FORMAT_XBGR8888,
+	DRM_FORMAT_RGB888,
+	DRM_FORMAT_BGR888,
 	DRM_FORMAT_XRGB16161616,
 	DRM_FORMAT_XBGR16161616,
 	DRM_FORMAT_ARGB16161616,