drivers: qcom: mpm: Use irqchip declare macro to init mpm-gpio controller

Use IRQCHIP_DECLARE macro to initialize mpm gpio controller instead
of platform device probe.

Change-Id: I7d5e19e43ce32f2056aa27dba2e132bcd2b3d1e3
Signed-off-by: Raghavendra Kakarla <rkakarla@codeaurora.org>