UPSTREAM: [media] cec: fix Kconfig dependency problems

- Use IS_REACHABLE(RC_CORE) instead of IS_ENABLED: if cec is built-in and
  RC_CORE is a module, then CEC can't reach the RC symbols.
- Both cec and cec-edid should be bool and use the same build 'mode' as
  MEDIA_SUPPORT (just as is done for the media controller code).
- Add a note to staging that this should be changed once the cec framework
  is moved out of staging.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Reported-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
(cherry picked from commit 5bb2399a4f)

Change-Id: I7a5812f3784b0a52f0e3545582a35032e9b7ba3f
Signed-off-by: Nickey Yang <nickey.yang@rock-chips.com>

drivers/media/Kconfig

@@ -81,7 +81,7 @@ config MEDIA_RC_SUPPORT
 	  Say Y when you have a TV or an IR device.
 
 config MEDIA_CEC_EDID
-	tristate
+	bool
 
 #
 # Media controller

drivers/media/Makefile

@@ -2,7 +2,9 @@
 # Makefile for the kernel multimedia device drivers.
 #
 
-obj-$(CONFIG_MEDIA_CEC_EDID) += cec-edid.o
+ifeq ($(CONFIG_MEDIA_CEC_EDID),y)
+  obj-$(CONFIG_MEDIA_SUPPORT) += cec-edid.o
+endif
 
 media-objs	:= media-device.o media-devnode.o media-entity.o