kconfig: Remove log backend options from MCUMGR configuration
kconfig: Remove log backend options from MCUMGR configuration

The log handler source does not compile for quite long now.

Signed-off-by: Dominik Ermel <1a1d45a9cc0c98a37f8d0a0d2dbe3cacc0b2344f@nordicsemi.no>

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