wl1271: Remove device MAC-address randomization

This patch removes the MAC address randomization from the driver. This removes
a nasty Nokia-OUI dependency from the driver.

With this patch, unless an address is explicitly configured to the driver
by the user, only a zero address will be configured, and the driver will be
unable to start.

Signed-off-by: Juuso Oikarinen <juuso.oikarinen@nokia.com>
Reviewed-by: Teemu Paasikivi <ext-teemu.3.paasikivi@nokia.com>
Signed-off-by: Luciano Coelho <luciano.coelho@nokia.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>