shmobile_init_delay() looks for OF "clock-frequency" to determine
the delay which is set by calling shmobile_setup_delay().

Unfortunately this seems to be incorrect in detail as
"clock-frequency" node values are in HZ whereas the frequency
argument to shmobile_setup_delay() is in MHz.

Provide a variant of shmobile_setup_delay() that accepts HZ to
correct this problem.
Signed-off-by: Simon Horman <horms+renesas@verge.net.au>