[media] rc: rename the remaining things to rc_core

The Remote Controller subsystem is meant to be used not only by Infra Red
but also for similar types of Remote Controllers. The core is not specific
to Infra Red. As such, rename:
	- ir-core.h to rc-core.h
	- IR_CORE to RC_CORE
	- namespace inside rc-core.c/rc-core.h

To be consistent with the other changes.

No functional change on this patch.

Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/rc/rc-core-priv.h b/drivers/media/rc/rc-core-priv.h
index 3616c32..48065b7 100644
--- a/drivers/media/rc/rc-core-priv.h
+++ b/drivers/media/rc/rc-core-priv.h
@@ -18,7 +18,7 @@
 
 #include <linux/slab.h>
 #include <linux/spinlock.h>
-#include <media/ir-core.h>
+#include <media/rc-core.h>
 
 struct ir_raw_handler {
 	struct list_head list;