mtkmodem: rename struct mtk_data instances to md

Signed-off-by: You-Sheng Yang <vicamo@gmail.com>
mtkmodem: rename GRil instances to ril

Signed-off-by: You-Sheng Yang <vicamo@gmail.com>
mtkmodem: rename struct ofono_modem instances to modem

Signed-off-by: You-Sheng Yang <vicamo@gmail.com>
rilmodem: rename struct ril_data instances to rd

Signed-off-by: You-Sheng Yang <vicamo@gmail.com>
rilmodem: rename GRil instances to ril

Signed-off-by: You-Sheng Yang <vicamo@gmail.com>
rilmodem: query network selection mode

Signed-off-by: You-Sheng Yang <vicamo@gmail.com>
mtkmodem: optionally use RIL_REQUEST_RADIO_POWER

Some MTK devices do not have RIL_REQUEST_RADIO_POWERON/OFF, so fall
back to generic RIL_REQUEST_RADIO_POWER here if environment variable
"OFONO_MTK_NO_POWERON_POWEROFF" is *NOT* set.

Signed-off-by: You-Sheng Yang <vicamo@gmail.com>
mtkmodem: add dummy RIL_REQUEST_DISABLE_VT_CAPABILITY

Signed-off-by: You-Sheng Yang <vicamo@gmail.com>
mtkmodem: add RIL_REQUEST_STORE_MODEM_TYPE

Signed-off-by: You-Sheng Yang <vicamo@gmail.com>