board/radxa/rock5b: fix kernel patch location

Commit 2a5d90a59516 (configs/rock5b: Add patches to fix gcc12 warnings)
introduced the kernel patches in an incorrect directory.

Fix that by moving them in the proper location.

Reported-by: Kilian Zinnecker <kilian.zinnecker@mail.de>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>