arm64: Remove duplicate included header

The header asm/unistd_compat_32.h is included whether CONFIG_COMPAT is
defined or not.

Include it only once and remove the following make includecheck warning:

  asm/unistd_compat_32.h is included more than once

Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20250109104636.124507-2-thorsten.blum@linux.dev


Signed-off-by: Will Deacon <will@kernel.org>