curve448/field.h: relax alignment, as it doesn't work universally.
curve448/field.h: relax alignment, as it doesn't work universally.

Some platforms, cough-DJGPP, fail to compile claiming that requested
alignment is greater than maximum possible. Supposedly original
alignment was result of an attempt to utilize AVX2...

Reviewed-by: Rich Salz <c04971a99e5a9ee80eaab4b1deb37e845b0bd697@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/5708)

openssl/openssl,openssl/openssl,openssl/openssl,openssl/openssl,openssl/openssl,openssl/openssl