drivers: pinctrl: msm: remove redundant call to set handler

The gpiochip_add_data() sets the chained irq handler for the TLMM
summary line. Remove reundant call to set the handler again.

Change-Id: I230f21fdde880407bf84ac73669457aa062a8236
Signed-off-by: Lina Iyer <ilina@codeaurora.org>