drm/amdgpu: Update Kconfig help for SI and CIK support

Signed-off-by: Felix Kuehling <Felix.Kuehling@amd.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Acked-by: Michel Dänzer <michel.daenzer@amd.com>

drivers/gpu/drm/amd/amdgpu/Kconfig

@@ -5,15 +5,23 @@ config DRM_AMDGPU_SI
 	  Choose this option if you want to enable experimental support
 	  for SI asics.
 
+	  SI is already supported in radeon. Experimental support for SI
+	  in amdgpu will be disabled by default and is still provided by
+	  radeon. Use module options to override this:
+
+	  radeon.si_support=0 amdgpu.si_support=1
+
 config DRM_AMDGPU_CIK
 	bool "Enable amdgpu support for CIK parts"
 	depends on DRM_AMDGPU
 	help
-	  Choose this option if you want to enable experimental support
-	  for CIK asics.
+	  Choose this option if you want to enable support for CIK asics.
+
+	  CIK is already supported in radeon. If you enable this option,
+	  support for CIK will be provided by amdgpu and disabled in
+	  radeon by default. Use module options to override this:
 
-	  CIK is already supported in radeon.  CIK support in amdgpu
-	  is for experimentation and testing.
+	  radeon.cik_support=1 amdgpu.cik_support=0
 
 config DRM_AMDGPU_USERPTR
 	bool "Always enable userptr write support"