bsaes-armv7.S implements bsaes_cbc_encrypt if #if __ARM_MAX_ARCH__ >= 7
but e_aes.c instead used #if __ARM_ARCH >= 7 causing duplicate symbols
for linkers that care about that
Change-Id: I10ad8e24be75fdc03b0670869a53078b0477950b
Reviewed-on: https://boringssl-review.googlesource.com/4943
Reviewed-by: Adam Langley <agl@google.com>