OMAP3: PM: Program correct init voltages for VDD1 and VDD2

By default the system boots up at nominal voltage for every
voltage domain in the system. This patch puts VDD1 and VDD2
to the correct boot up voltage as per the opp tables specified.
This patch implements this by matching the rate of the main clock
of the voltage domain with the opp table and picking up the correct
voltage.

Signed-off-by: Thara Gopinath <thara@ti.com>
Signed-off-by: Kevin Hilman <khilman@deeprootsystems.com>