serial: msm_geni_serial: Remove manual flow control and set as RFR OPEN

This patch removes the manual flow control and instead gives the RFR
control to the HW depending on the FIFO level. In case of Manual flow
control FW introduced a race and caused RFR to remain High at RX shutdown
which blocked peer device from sending any data.

The latest FW along with this patch makes sure RFR gets configured as an
RFR OPEN post RX cancel and removes the need to have any manual flow. Also
wait for the RX EOT bit post cancel command as per the suggested sequence.

Also Log the GENI FW version for primary and secondary sequencer.

Change-Id: Ifc06a3f1c971eb7490ff8e678779e7163008f999
Signed-off-by: Mukesh Kumar Savaliya <msavaliy@codeaurora.org>