meta-agl-bsp: remove obsolete Raspberry Pi kernel patch

meta-agl-bsp: remove obsolete Raspberry Pi kernel patch

Remove patch to reenable memory cgroups support, as it is no longer
necessary with the latest kernel bump in meta-raspberrypi (upstream
has moved to a kernel command-line option for disabling instead).

Bug-AGL: SPEC-5392

Change-Id: I48d49354c7db9d7eaa71da241f96de0a05cf931f
Signed-off-by: Scott Murray <scott.murray@konsulko.com>
Reviewed-on: https://gerrit.automotivelinux.org/gerrit/c/AGL/meta-agl/+/30897
ci-image-build: Jenkins Job builder account
Tested-by: Jenkins Job builder account
Reviewed-by: Jan-Simon Moeller <jsmoeller@linuxfoundation.org>
ci-image-boot-test: Jenkins Job builder account