net: rmnet_data: Modifying the ingress handler to support MAP bridging

This patch modified the main ingress handler to not drop MAP packets
when in bridge mode. This is required to support bridging of MAP
packets between two endpoints.

CRs-Fixed: 590888
Change-Id: If0b6f6434ec95c36e0f46bbe70ea65fa50b03b15
Acked-by: David Arinzon <darinzon@qti.qualcomm.com>
Signed-off-by: Harout Hadeshian <harouth@codeaurora.org>