ibcore: Validate port number in query_pkey verb.

Before calling the driver's function let's make sure port is valid.

Linux commit:
9af3f5cf9d64a056eca53bc643f6288ad28bbbb5

Reviewed by: kib
Sponsored by: Mellanox Technologies // NVIDIA Networking

(cherry picked from commit 31525faed8b43c579767cf3ac211f41764b2a46c)