video: Rename CONFIG_DM_VIDEO to CONFIG_VIDEO

Now that all the old code is gone, rename this option. Driver model
migration is now complete.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/configs/stm32mp15_trusted_defconfig b/configs/stm32mp15_trusted_defconfig
index 9cfa9a2..3309c2e 100644
--- a/configs/stm32mp15_trusted_defconfig
+++ b/configs/stm32mp15_trusted_defconfig
@@ -145,7 +145,7 @@
 CONFIG_USB_GADGET_VENDOR_NUM=0x0483
 CONFIG_USB_GADGET_PRODUCT_NUM=0x5720
 CONFIG_USB_GADGET_DWC2_OTG=y
-CONFIG_DM_VIDEO=y
+CONFIG_VIDEO=y
 CONFIG_BACKLIGHT_GPIO=y
 CONFIG_VIDEO_LCD_ORISETECH_OTM8009A=y
 CONFIG_VIDEO_LCD_RAYDIUM_RM68200=y