ARM: dts: msm: reduce VDD_GFX CPR max floor to ceiling range for MSM8998v2

Reduce the VDD_GFX CPR maximum floor to ceiling voltage range for
each corner in order to meet the most recent hardware guidelines.

Change-Id: Ie70a698fbed442e8826f0bc30c5ef6bdfd5b3e1f
CRs-Fixed: 1098577
Signed-off-by: David Collins <collinsd@codeaurora.org>