Add some standard functions to convert between different byte orders.
Conveniently the UAPI headers provide all the necessary functionality.
Signed-off-by: Thomas Weißschuh <linux@weissschuh.net>
Acked-by: Willy Tarreau <w@1wt.eu>
Link: https://patch.msgid.link/20260405-nolibc-bswap-v1-1-f7699ca9cee0@weissschuh.net
