ARM: shmobile: Add r8a73a4 CMT10 clock event

Add clock event support for CMT1 timer channel 0
to the r8a73a4 SoC code. The CMT is used together
with a 32KHz clock in this case.

Signed-off-by: Magnus Damm <damm@opensource.se>
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>