msm: emac: Don't generate random mac address

Remove random mac address generation since the firmware
always pass the mac-address parameter through _DSD method.
Display an error message and bail out the driver
probe() in case mac address is not valid.

Change-Id: I26eebc679f6e7a831e03aa7137fa38ff81232bcd
Signed-off-by: Shanker Donthineni <shankerd@codeaurora.org>
Signed-off-by: Gilad Avidov <gavidov@codeaurora.org>
Signed-off-by: Alok Chauhan <alokc@codeaurora.org>