Input: snvs_pwrkey - initialize necessary driver data before enabling IRQ

Input: snvs_pwrkey - initialize necessary driver data before enabling IRQ

SNVS IRQ is requested before necessary driver data initialized,
if there is a pending IRQ during driver probe phase, kernel
NULL pointer panic will occur in IRQ handler. To avoid such
scenario, just initialize necessary driver data before enabling
IRQ. This patch is inspired by NXP's internal kernel tree.

Fixes: d3dc6e232215 ("input: keyboard: imx: add snvs power key driver")
Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>