msm: add tlmm support for gpio.

GPIO support for Qualcomm SOCs requires interaction with the
radio (baseband processor). This API allows the different boards
to enable GPIO through the radio processor in a generic way.

Signed-off-by: Gregory Bean <gbean@codeaurora.org>
Signed-off-by: David Brown <davidb@codeaurora.org>
Signed-off-by: Daniel Walker <dwalker@codeaurora.org>
Signed-off-by: Abhijeet Dharmapurikar <adharmap@codeaurora.org>
Signed-off-by: Stepan Moskovchenko <stepanm@codeaurora.org>