net: wireless: bcmdhd: Check if FW is up during SAR setup

Added extra check to see if FW is up and running before we try to
setup SAR and if ther is no return error.

Bug: 23464710
Bug: 23481741

Change-Id: If3bab41594995baffc5749d6f431ec10bcfd8a66
Signed-off-by: Ashwin <ashwin.bhat@broadcom.com>
Signed-off-by: Dmitry Shmidt <dimitrysh@google.com>