mach: msm: remove msm_mpm_pin enum from mpm.h

Value of MSM_MPM_PIN_* in msm_mpm_pin enum may be target
dependent so it's not good to keep them in generic mpm.h
file. So let's remove it from mpm.h and let client of these
APIs to pass their own interrupt number to these APIs.

Change-Id: I5360648ab10c7256ee4a6067bfb83314b311137b
Signed-off-by: Subhash Jadavani <subhashj@codeaurora.org>