.buildkite: run.sh: Install lpc_checksum package
.buildkite: run.sh: Install lpc_checksum package

The sanitycheck tests are all failing for the lpcxpresso11u68 board
because the lpc_checksum, a new python script requirement introduced
by this board, is not present in the build environment. This
commit attempt to fix this issue by installing lpc_checksum before
running sanitycheck.

Signed-off-by: Maxime Bittan <95b2a4134501ceceecb5f13a29f980883943b7de@seagate.com>

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