ARM: OMAP: Add arch_cpu_init function

The boot parameters passed from SPL to UBOOT
must be saved as a part of uboot's gd data
as early as possible, before we will inadvertently
overwrite it. So adding a arch_cpu_init for the required
Socs to save it.

Signed-off-by: Sricharan R <r.sricharan@ti.com>
[trini: Add igep0033 hunk]
Signed-off-by: Tom Rini <trini@ti.com>