kernel: Remove patch for fixed bug

kernel: Remove patch for fixed bug

The problem was fixed in upstream kernel in a different way and the
change was backported to kernel 6.6 in the following change:
https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?h=linux-6.6.y&id=48e8791843206baf76827df1b6ee3cb88a2a17d8

The removed patch changes the endianness again and breaks the
functionality, use only the upstream code and remove our unneeded patch.

The 823-v6.12-0003-nvmem-layouts-add-U-Boot-env-layout.patch patch was
adapted in the kernel bump too. It moves the code with the fix now.

Fixes: 05d344cb2ca3 ("kernel: bump 6.6 to 6.6.100")
Reported-by: Michael Pratt <mcpratt@pm.me>
Link: https://github.com/openwrt/openwrt/pull/19830
(cherry picked from commit 4cd256c72a7e823e55475786eb1f2a1f7ffcd497)
Link: https://github.com/openwrt/openwrt/pull/19839
Signed-off-by: Hauke Mehrtens <hauke@hauke-m.de>