Bootloader marks frames used for the ramdisk as MemoryRegionKind::Usable when using Uefi

[daniel-keitel]

Frames in which the ramdisk is stored may be reported as usable in a memory region, when using Uefi.

Tested on hardware (i9-13900K) and qemu.

Workaround:

• get physical address range of ramdisk (should be contiguous)
• prevent frames in this range from being used

[phil-opp]

Thanks a lot for reporting! I prepared a fix in #408.