ARC: [plat*] move code out of .init_machine into common

All the platforms do the same thing in init_machine callback so move it
out of callback into caller of callback

Signed-off-by: Vineet Gupta <vgupta@synopsys.com>

arch/arc/Kconfig

@@ -9,6 +9,7 @@
 config ARC
 	def_bool y
 	select BUILDTIME_EXTABLE_SORT
+	select COMMON_CLK
 	select CLONE_BACKWARDS
 	# ARC Busybox based initramfs absolutely relies on DEVTMPFS for /dev
 	select DEVTMPFS if !INITRAMFS_SOURCE=""