tests/tcg/sha1: remove endian include

This doesn't exist in BSD world and doesn't seem to be needed by
either.

Signed-off-by: Alex Bennée <alex.bennee@linaro.org>
Reviewed-by: Warner Losh <imp@bsdimp.com>
Message-Id: <20210917162332.3511179-3-alex.bennee@linaro.org>