msm: ipa: teth_bridge: register to IPA RM for A2_PROD events

Register for A2_PROD events, such as RESOURCE_GRANTED and
RESOURCE_RELEASED. By getting the notifications, bridge driver will be
able to configure A2 pipes at the right time.

This fix enables USB suspend/resume scenario and also fixes a hidden bug
in Ethernet link protocol during the same scenario.

Change-Id: I2f6171f2a86d158cea3f0d208159754ef930231f
Signed-off-by: Vladislav Mordohovich <vmordoho@codeaurora.org>
Signed-off-by: Gidon Studinski <gidons@codeaurora.org>