drm/bridge: it6505: Remove useless select

The IT6505 bridge Kconfig symbol selects a Kconfig symbol that doesn't
exist. Remove it.
Reviewed-by: Jani Nikula <jani.nikula@intel.com>
Link: https://lore.kernel.org/r/20240327-kms-kconfig-helpers-v3-13-eafee11b84b3@kernel.orgSigned-off-by: Maxime Ripard <mripard@kernel.org>

drivers/gpu/drm/bridge/Kconfig

@@ -98,7 +98,6 @@ config DRM_ITE_IT6505
 	depends on DRM_DISPLAY_HELPER
 	depends on OF
 	select DRM_KMS_HELPER
-	select DRM_DP_HELPER
 	select EXTCON
 	select CRYPTO
 	select CRYPTO_HASH