ARM: shmobile: Add SMP boot function and argument

Add code for mach-shmobile to allow specifying boot function
and argument. Will initially be used for SMP together with SCU
but may in the future also be used for deep sleep resume. This
patch removes one inline virtual to physical address conversion.

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