pinctrl: msm: don't assume pintype irqchip is configured always

If legacy tlmm irq chip is being used, pinctrl irq domain would not be
allocated so enabled irq bits won't represent irqs actually enabled.
Currently this results in improper irqs enable and disable during
suspend/resume.  Check if own irqdomain is initialized.

Change-Id: Ic5381413ff740a55244e3fedcae67131de0b4a6e
Signed-off-by: Joonwoo Park <joonwoop@codeaurora.org>