msm_serial_hs: Use RFR GPIO to communicate remote uart

CTS and RFR GPIOs are used for hardware flow control between
two uarts. RFR GPIO provides current status of uart receiver
to remote uart and based on this remote uart sends data.
Hence use this functionality to prevent remote uart to send
data when port is being opened, baud rate change operation
is in progress and port is being closed.

This change also set UART_DM_MR2 (Bit: 8 and 9) before
configuring connected UART GPIOs to prevent RX_BREAK character
and any character having PARTIY or FRAMING error which can be
generated due to configuration of those GPIOs. Allows those
character once port is opened successfuly.

This change also zeroed uart rx software buffer which would
help to see how many bytes copied by ADM from received data
with UART RX FIFO to this memory. This would be useful if
there is any Rx Stall issue is seen.

CRs-Fixed: 495564
Change-Id: I56e8990329959c541ba1dc90f5a4a0004a393a8e
Signed-off-by: Mayank Rana <mrana@codeaurora.org>
Merge "msm_serial_hs: Use RFR GPIO to communicate remote uart"
USB: gadget: Cleanup boot-up message with default usb composition

The print message with rmnet bind and adb_bind is enabled by default.
It appears for each default composition switch. Watchdog timeout is
seen if there is stability issue on device bootup with serial console
enable. Hence move message loglevel from pr_info to pr_debug to
resolve this issue.

CRs-Fixed: 499244
Change-Id: Ife129604a1d877a4c8c6b7cd7a75a6af2ff03578
Signed-off-by: Mayank Rana <mrana@codeaurora.org>
Merge "USB: gadget: Cleanup boot-up message with default usb composition"