powerpc/audit: Directly include unistd_32.h from compat_audit.c

powerpc/audit: Directly include unistd_32.h from compat_audit.c

This source file undefines '__powerpc64__' to get the 32-bit system call
numbers from asm/unistd.h. However this symbol is also evaluated by
other headers, among them is asm/bitsperlong.h. The undefinition leads
to an inconsistency between __BITS_PER_LONG and the C type 'long'.
An upcoming consistency check will be tripped by this.

Directly include asm/unistd_32.h to get access to the 32-bit system call
numbers instead.

Signed-off-by: Thomas Weißschuh <thomas.weissschuh@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Link: https://patch.msgid.link/20260302-vdso-compat-checkflags-v2-4-78e55baa58ba@linutronix.de