spmi and gpio: qpnp: add pointer check in qpnp drivers

This patch is to fix KW errors in drivers. It's
neccessary to check NULL pointer before dereferencing it.
There're 4 issues related to it in qpnp-int.c and
qpnp-pin.c. Fix them by checking before.

CRs-Fixed: 505322
Change-Id: I2f82d1b24c219ef7e6b0977091fc353dac579cbc
Signed-off-by: Zhenhua Huang <zhenhuah@codeaurora.org>