msm_serial_hs: Don't configure gpios into UART Mode always

UARTDM device is used as interface to connect external devices through
GPIOs. Currently those GPIOs are configured in active mode once driver's
probe() is called and configured in suspend mode once its remove() is
called. Probe() is called once only and remove is not called until UARTDM
platform device is removed. With this current implementation, although
external device (ex. Bluetooth SoC) is not operational mode, used UARTDM
GPIOs are configured in active mode which is causing more leakage current
and more power consumption.

Hence configure those UARTDM GPIOs in active mode only when used UARTDM
device is opened and under used. Configure UARTDM GPIOs back to suspend
mode when UARTDM device is closed and under not used.

CRs-Fixed: 422217

Change-Id: I057a2da827f37687e5ea69bdca1533568be06eab
Signed-off-by: Mayank Rana <mrana@codeaurora.org>
Signed-off-by: Neha Pandey <nehap@codeaurora.org>