multiboot2: add missing tags #1019

Job	Run time
build (msrv) / rust	21s
build (nightly) / rust	29s
build (stable) / rust	15s
build no_std (stable) [Windows] / rust	56s
build no_std (stable) [w/o builder] / rust	10s
build no_std (stable) / rust	13s
style (stable) / rust	14s
build no_std (msrv) / rust	24s
style (msrv) / rust	24s
style (nightly) / rust	17s
build no_std (nightly) / rust	20s
tests with miri (nightly) / rust	52s
	4m 55s

Provide feedback