git: don't use review.coreboot.org as main

where backup links are available, use those as main instead.

this is because of the new XBMK_CACHE_MIRROR variable, which
makes --mirror be used

when performed on review.coreboot.org, this also pulls down
all changes from gerrit code review; the github backups for
example only contain the official branches, but gerrit creates
a new ref per merge request.

a user can still run ./mk -F to force pulling all repos,
including the coreboot.org ones, but use of -f will skip the
coreboot.org ones if the backup links worked and contain the
local commit needed, by a given project used in xbmk.

this patch won't change any real-world behaviour for xbmk
users, but it is done as a courtesy to the coreboot project,
in that it largely avoids a sudden surge in coreboot.org's
traffic if lots of users start doing XBMK_CACHE_MIRROR=y

if XBMK_CACHE_MIRROR is not set, or set to anything other
than y, a regular clone is performed, saving cached sources
to cache/clone/ - otherwise, cache/mirror/ is used.

Signed-off-by: Leah Rowe <leah@libreboot.org>

config/git/bios_extract/pkg.cfg

@@ -1,5 +1,5 @@
 # SPDX-License-Identifier: GPL-3.0-or-later
 
 rev="0a7bc1d71735ef97b00dfec0fd54a02fcc5d1bb0"
-url="https://review.coreboot.org/bios_extract"
-bkup_url="https://github.com/coreboot/bios_extract"
+url="https://github.com/coreboot/bios_extract"
+bkup_url="https://review.coreboot.org/bios_extract"

config/git/coreboot/pkg.cfg

@@ -1,5 +1,5 @@
 # SPDX-License-Identifier: GPL-3.0-or-later
 
 rev="HEAD"
-url="https://review.coreboot.org/coreboot"
-bkup_url="https://github.com/coreboot/coreboot.git"
+url="https://github.com/coreboot/coreboot.git"
+bkup_url="https://review.coreboot.org/coreboot"

config/git/deguard/pkg.cfg

@@ -1,5 +1,5 @@
 # SPDX-License-Identifier: GPL-3.0-or-later
 
 rev="0ed3e4ff824fc42f71ee22907d0594ded38ba7b2"
-url="https://review.coreboot.org/deguard"
-bkup_url="https://codeberg.org/libreboot/deguard"
+url="https://codeberg.org/libreboot/deguard"
+bkup_url="https://review.coreboot.org/deguard"

config/git/seabios/pkg.cfg

@@ -1,5 +1,5 @@
 # SPDX-License-Identifier: GPL-3.0-or-later
 
 rev="HEAD"
-url="https://review.coreboot.org/seabios"
-bkup_url="https://github.com/coreboot/seabios"
+url="https://github.com/coreboot/seabios"
+bkup_url="https://review.coreboot.org/seabios"