msm: generialize iomap to support multiple SOCs.

msm_iomap.h is specific to the MSM7x00 series devices.  Generalize
this in preparation to support more devices.

Signed-off-by: Gregory Bean <gbean@codeaurora.org>
Signed-off-by: David Brown <davidb@codeaurora.org>
Signed-off-by: Daniel Walker <dwalker@codeaurora.org>
Signed-off-by: Abhijeet Dharmapurikar <adharmap@codeaurora.org>
Signed-off-by: Stepan Moskovchenko <stepanm@codeaurora.org>