factorise some generic infrastructure to assist looking up struct clks
for the ARM & SH architecture.
as the code is identical at 99%
put the arch specific code for allocation as example in asm/clkdev.h
Signed-off-by: Jean-Christophe PLAGNIOL-VILLARD <plagnioj@jcrosoft.com> Acked-by: Paul Mundt <lethal@linux-sh.org> Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>