Renames linux-postmarketos-apple to linux-postmarketos-apple-4k to represent the page size as linux-postmarketos-apple-16k does. Also upgrades the kernel version to 6.16.0-rc1. Signed-off-by: Aster Boese <asterboese@mailbox.org> Part-of: https://gitlab.postmarketos.org/postmarketOS/pmaports/-/merge_requests/6733