ARM: dts: msm: increase the haptic vmax for 8996 DTP

Haptic device node is defined by PMI8994. Haptics module
provides the vibration effects for the device. Increase
the max voltage to strengthen the vibration which is too
weak to feel. change the driver mode to erm.

Change-Id: I16234357422ef006e14f451f4c2b93fc2cd3944e
Signed-off-by: Mao Li <maol@codeaurora.org>