arm: omap3: pm34xx.c: Replace printk() with appropriate pr_*()

Currently, pm34xx.c has a mix of printk() and pr_*() statements
so replace the printk() statements with the equivalent pr_*()
statements.

Signed-off-by: Mark A. Greer <mgreer@animalcreek.com>
Signed-off-by: Kevin Hilman <khilman@ti.com>