maintainers: Add myself as collaborator
maintainers: Add myself as collaborator

Adds myself as a collaborator to SPI and the system timer

Signed-off-by: Tom Burdick <63c280986e32082c9e27a1a69ac8b19e3d0c6b4b@intel.com>

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