drm/arm: arm hdlcd select DRM_GEM_CMA_HELPER

Without DRM_GEM_CMA_HELPER HDLCD won't build. This needs to be there too.

Fixes: 09717af7 ("drm: Remove CONFIG_DRM_KMS_CMA_HELPER option")
Reviewed-by: Steven Price <steven.price@arm.com>
Signed-off-by: Carsten Haitzler <carsten.haitzler@arm.com>
Acked-by: Liviu Dudau <liviu.dudau@arm.com>
Signed-off-by: Rob Herring <robh@kernel.org>
Link: https://lore.kernel.org/r/20220124162437.2470344-1-carsten.haitzler@foss.arm.com

drivers/gpu/drm/arm/Kconfig

@@ -6,6 +6,7 @@ config DRM_HDLCD
 	depends on DRM && OF && (ARM || ARM64 || COMPILE_TEST)
 	depends on COMMON_CLK
 	select DRM_KMS_HELPER
+	select DRM_GEM_CMA_HELPER
 	help
 	  Choose this option if you have an ARM High Definition Colour LCD
 	  controller.