ARM: dts: msm: Update APC CPR voltage margins for MSM8937

Based on the characterization data update the CPR
closed-loop margins for APC CPR Rev 3.

CRs-Fixed: 986759
Change-Id: If219039a4a3f45e08eeb386d6f29e572c53ac40f
Signed-off-by: Anirudh Ghayal <aghayal@codeaurora.org>