dt-bindings: versal: Add new PM_DEV_I2C_PMC macro

Add new macro for PMC I2C power domain.

Signed-off-by: Sandeep Gundlupet Raju <sandeep.gundlupet-raju@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Link: https://lore.kernel.org/r/0bf164f937df551d689dda2a35f9489c2e46b4ab.1638277017.git.michal.simek@xilinx.com