ARM: shmobile: sh73a0: Always use shmobile_setup_delay()

Break out the function sh73a0_init_delay() that now
gets called both for the C version of the code and
the DT -reference boards. This way we handle both
cases in the same way.

Allows us to boot with TWD only in the kernel configuration
for C board code. TWD is not yet enabled in the case of
DT -reference - this due to a dependency on CCF.

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