net: stmmac: use correct header type

Set hdr type to IPA_HDR_L2_802_1Q while registering
Tx/Rx properties in case vlan offload enabled.

Change-Id: I9ecb27d08667ce2c8b26ac0bef79503bcb5241b2
Acked-by: Abhishek Chauhan <abchauha@qti.qualcomm.com>
Signed-off-by: Sunil Paidimarri <hisunil@codeaurora.org>