msm: pm2: Avoid calling "ioremap_nocache" in atomic context for 8x25

Callling "ioremap_nocache" in atomic context might sleep, and kernel
prints a big stack trace every time when the system coming out of PC.
Do an "ioremap_nocache" at the time of dirver initialization.

Change-Id: I46651ddb0650ca8dd6db5c8e9eba8afc1e2d4ca9
Signed-off-by: Murali Nalajala <mnalajal@codeaurora.org>