imx: 6-12: refresh patches and kernel configs

imx: 6-12: refresh patches and kernel configs

patches:
 - remove patches from 6.7-6.12 that are now upstream.
 - refresh remaining patches
 - 502-6.13-arm64-dts-freescale-rename-gw7905-to-gw75xx.patch was
   misnamed as that patch went upstream in 6.12 and thus is also removed
 - 504-6.13-arm64-dts-imx-Add-i.MX8M-Plus-Gateworks-GW82XX-2X-support.patch
   was refreshed to the final version that was accepted upstream
 - 600-PCI-imx6-Start-link-at-max-gen-first-for-IMX8MM-and-IMX8MP.patch
   was removed while I investigate an upstream approach for the issue
   it was working around.

configs:
 - config-6.12: unset new configs not needed for all cortexa7/a9/a53
 - cortexa53/config-default: added new CONFIG_PCI_IMX6_HOST config for cortexA53 (IMX8M)

Signed-off-by: Tim Harvey <[email protected]>
Link: https://github.com/openwrt/openwrt/pull/19029
Signed-off-by: Nick Hainke <[email protected]>