wlan: Fix for improper comparison of driver_status string

This commit ensures driver load failure status is compared with
valid string which has the failure/success information.

Change-Id: I3b619ad0c005fb793d127bd2a23b376ed961d0b7
CRs-Fixed: 652539
wifi: avoid crash when no phy's are found

Exit gracefully when no phy's are found.

Change-Id: I8c1f57e60bb63b52d8cb086e1a25d8d5b33f03f0
Signed-off-by: Vishal Mahaveer <vishalm@ti.com>