drivers: Warning fixes to disable CC_OPTIMIZE_FOR_SIZE

These are all driver changes needed for disablement of
CONFIG_CC_OPTIMIZE_FOR_SIZE. CONFIG_CC_OPTIMIZE_FOR_PERFORMANCE
is enabled by default once CONFIG_CC_OPTIMIZE_FOR_SIZE is disabled.

Change-Id: Ia46a1f24e8a082a29ea6151e41e6d3a85a05fd4f
Signed-off-by: Prasad Sodagudi <psodagud@codeaurora.org>
Signed-off-by: Sridhar Parasuram <sridhar@codeaurora.org>