iwlwifi: mvm: take the MAC address from HW registers

For some configurations, the driver should get the MAC
address from the hardware registers and not from the
regular locations. Since the parsing of the MAC address
is the same regardless of its source, continue the regular
code path (parsing) after we read the registers.

Signed-off-by: Eran Harary <eran.harary@intel.com>
Signed-off-by: Emmanuel Grumbach <emmanuel.grumbach@intel.com>