drivers: modem: improve modem context RSSI member

The previous bf68b67 commit incorrectly passes minfo.mdm_rssi
value to the modem context data_rssi member during the driver
initialization which causes the `modem info` shell command
to return 0 as RSSI value. Fix that by changing data_rssi
modem ctx member to a pointer that is assigned to the RSSI
variable stored within the modem driver context structure.

Signed-off-by: Bartosz Bilas <bartosz.bilas@hotmail.com>
9 files changed