Change in flashrom[master]: internal: Return early from map_flash for >16MiB on x86

[Tim Wawrzynczak (Code Review)]

Attention is currently required from: Nico Huber, Furquan Shaikh, Edward O'Callaghan.
Hello build bot (Jenkins), Furquan Shaikh, Edward O'Callaghan,

I'd like you to reexamine a change. Please visit

https://review.coreboot.org/c/flashrom/+/56721

to look at the new patch set (#3).

Change subject: internal: Return early from map_flash for >16MiB on x86
......................................................................

internal: Return early from map_flash for >16MiB on x86

In the case of a flash chip bigger than 16 MiB, x86 chipsets are only
able to map the topmost 16 MiB of the chip into memory. To access the
rest, flashrom can use hardware sequencing, therefore return early from
`physmap_common()` in this situation; this avoids messages like the
following in Linux kernel logs:

[   57.715654] x86/PAT: flashrom:2805 conflicting memory types fe0000...
[   57.726270] x86/PAT: memtype_reserve failed [mem 0xfe000000-0xffff...

BUG=b:185021901
TEST=On a system with a W25Q256.V (32MB), flashrom logs show:
$ flashrom -p host -r bios.bin
...
Found Winbond flash chip "W25Q256.V" (32768 kB, Programmer-specific) ...
Chipset unable to map >16 MiB of flash
Reading flash... done.
SUCCESS

Signed-off-by: Tim Wawrzynczak 
Change-Id: I60244b6970118dbdfdbb5b8424fc0a8acd9def2e
---
M physmap.c
1 file changed, 9 insertions(+), 0 deletions(-)

git pull ssh://review.coreboot.org:29418/flashrom refs/changes/21/56721/3