msm: ipa4: flow control changes for rmnet pipe

When the RMNET pipe channel in the started state receiving the
junk packets, it leading IPA HW stall. Add changes to support
the new flow control channel state for rmnet pipe, it avoids
entering the junk packet to IPA HW.

Change-Id: If2b3992e8cdc93343e70f9d2c1783bbbde329bc2
Signed-off-by: Ashok Vuyyuru <avuyyuru@codeaurora.org>