x86: e820 regression

The following commit introduced a regression on my system.

124049decbb121ec32742c94fb5d9d6bed8f24d8 x86/e820: put !E820_TYPE_RAM regions into memblock.reserved

and it was backported to stable, stopping the kernel to boot on my system since around 4.17.4. It was reverted on upstream a couple months ago. commit 2a5bda5a624d6471d25e953b9adba5182ab1b51f upstream

There are some other modifications to the file after that. However, at the very least, can the revert be backported?

I think the original patch tries to fix a previous bug, so probably the latest commits fixed that one correctly and need to be backported as well.