ARM: dts: msm: Add shared gpio node for I2C flash for holi Pro

This change adds support in device-tree for sharing gpio
among multiple nodes. Gpio sharing among nodes enables
each camera to have its own unique I2C flash node.

CRs-Fixed: 2976840
Change-Id: Ib4ab92908b51c17f806e5acf2abe86cf41707e43