ARM: dts: msm: add batterydata to pmi8998 FG for msm8998 MTP and QRD

Add batterydata phandle to pmi8998 FG device so that it can be
used for obtaining the battery profiles that is required for
msm8998 MTP and QRD platforms.

Change-Id: I2255cd6475f3e49394cbdf3dd4594cb96fd70c31
Signed-off-by: Subbaraman Narayanamurthy <subbaram@codeaurora.org>