Building a multi-arch kernel results in:

arch/arm/crypto/built-in.o: In function `aesbs_xts_decrypt':
sha1_glue.c:(.text+0x15c8): undefined reference to `bsaes_xts_decrypt'
arch/arm/crypto/built-in.o: In function `aesbs_xts_encrypt':
sha1_glue.c:(.text+0x1664): undefined reference to `bsaes_xts_encrypt'
arch/arm/crypto/built-in.o: In function `aesbs_ctr_encrypt':
sha1_glue.c:(.text+0x184c): undefined reference to `bsaes_ctr32_encrypt_blocks'
arch/arm/crypto/built-in.o: In function `aesbs_cbc_decrypt':
sha1_glue.c:(.text+0x19b4): undefined reference to `bsaes_cbc_encrypt'

This code is already runtime-conditional on NEON being supported, so
there's no point compiling it out depending on the minimum build
architecture.
Acked-by: Ard Biesheuvel <ard.biesheuvel@linaro.org>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>