crypto: caam - replace deprecated EXTRA_CFLAGS

EXTRA_CFLAGS is still supported but its usage is deprecated.

Signed-off-by: Tudor Ambarus <tudor-dan.ambarus@nxp.com>
Reviewed-by: Horia Geantă <horia.geanta@nxp.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>