crypto: ux500 - use ccflags-y instead of CFLAGS_<basename>.o

Instead of adding CFLAGS_<basename>.o to every file, let's use
ccflags-y, which is effective for all C files in the directory.

No behavior change.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>