msm: krait-regulator: Set phase count of ganged rails to 4

When the device boots up, the phase count of the ganged rails is set to
1. When the first core is brought online set the phase count to 4 to
support booting with maxcpus set to 4.

CRs-fixed: 474770
Change-Id: I176b88bf072019e1e7ca09ce8a600efd902a2747
Signed-off-by: Mahesh Sivasubramanian <msivasub@codeaurora.org>