wlan:Check priviledge permission for SET_BAND_CONFIG IOCTL

Kernel assumes all SET IOCTL commands are assigned with even
numbers. But in our WLAN driver, some SET IOCTLS are assigned with
odd numbers. This leads kernel fail to check, for some SET IOCTLs,
whether user has the right permission to do SET operation.
Hence, in driver, before processing SET_BAND_CONFIG IOCTL, making
sure user task has right permission to process the command.

CRs-Fixed: 930952
Git-commit: 6642bccf3ed8cba176dee7d4bbc21fc4580efb7b
Bug: 25344453
Signed-off-by: Amarnath Hullur Subramanyam <amarnath@codeaurora.org>