clocksource: sh_cmt: Add control register callbacks

This patch adds control register callbacks for the CMT
driver. At this point only 16-bit access is supported
but in the future this will be updated to allow 32-bit
access as well.

Signed-off-by: Magnus Damm <damm@opensource.se>
Acked-by: John Stultz <john.stultz@linaro.org>
Tested-by: Guennadi Liakhovetski <g.liakhovetski@gmx.de>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>

diff --cc drivers/clocksource/sh_cmt.c
Simple merge