c6x: remove unused COMMON_CLKDEV Kconfig parameter

This removes the COMMON_CLKDEV kernel configuration
parameter defined in arch/c6x/Kconfig, but used nowhere
in the makefiles and source code.
Signed-off-by: Michael Opdenacker <michael.opdenacker@free-electrons.com>
Signed-off-by: Mark Salter <msalter@redhat.com>

arch/c6x/Kconfig

@@ -36,9 +36,6 @@ config GENERIC_HWEIGHT
 config GENERIC_BUG
 	def_bool y
 
-config COMMON_CLKDEV
-	def_bool y
-
 config C6X_BIG_KERNEL
 	bool "Build a big kernel"
 	help