tests: kernel: context: Fix build issue with RV32M1_LPTMR_TIMER
tests: kernel: context: Fix build issue with RV32M1_LPTMR_TIMER

We needed to add support for the RV32M1_LPTMR_TIMER to the test so its
knows what the IRQ of the timer is.

Signed-off-by: Kumar Gala <a5e5248af4cd4f0ed8c515f61d40a6e2db46a66e@linaro.org>

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