msm: spm: Do not set the core voltage during driver initilization

The initial voltage value for the cores are setup by bootloaders for
Core 0. The voltages for the secondary cores are set by Core 0 before
bringing them out of reset. When the cores are out of reset, the SAW
regulator takes care of setting core voltage. Thereby we need not set
the voltage for the cores during SPM driver initialization.

Additionally the commit also reorders the SPM register enums to prevent
initiliazation of status registers.

CRs-fixed: 336256
Change-Id: I3d3d82c867a79f0002c1ea7ef61b017a447a7783
Signed-off-by: Mahesh Sivasubramanian <msivasub@codeaurora.org>