msm: platform: qpnp-clkdiv: fix potential null pointer dereference

Add a return statement in the spmi resource null check in
qpnp_clkdiv_probe().  This is needed in order to avoid
dereferencing a null pointer in a subsequent statement.

Change-Id: Iaf5d5797016c96a136e93c8e5837f7f8f31d1e47
CRs-Fixed: 563655
Signed-off-by: David Collins <collinsd@codeaurora.org>