Don't expect bsaes functions on ARMv6.

The bsaes-armv7.S asm has an #if __ARM_ARCH__>=7 around its contents,
i.e. it's not just switched at runtime – it only compiles for >= ARMv7.

I mistakenly regressed e_aes.c in 3e652657 to always expected bsaes
functions to exist on ARM. This change fixes that.

Change-Id: Ifd9111438508909a0627b25aee3e2f11e62e3ee8

crypto/cipher/e_aes.c

@@ -111,7 +111,7 @@ static char bsaes_capable(void) {
     (defined(OPENSSL_ARM) || defined(OPENSSL_AARCH64))
 #include "../arm_arch.h"
 
-#if defined(OPENSSL_ARM)
+#if defined(OPENSSL_ARM) && __ARM_ARCH__ >= 7
 #define BSAES
 static char bsaes_capable(void) {
   return CRYPTO_is_NEON_capable();