drivers: modem: hl7800: +KSRAT dependent on firmware version
drivers: modem: hl7800: +KSRAT dependent on firmware version

The reboot option of the +KSRAT command is only
supported by newer firmware.
Add a check to determine what version of the command
to use when setting the RAT.

Signed-off-by: Ryan Erickson <445db09b136432317bdbb8e4308a30651390c2e2@lairdconnect.com>

galak/zephyr,finikorg/zephyr,galak/zephyr,zephyrproject-rtos/zephyr,finikorg/zephyr,galak/zephyr,finikorg/zephyr,galak/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,galak/zephyr,finikorg/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr,zephyrproject-rtos/zephyr