bswap: Add st24_be_p() to store 24 bits in big-endian order

bswap: Add st24_be_p() to store 24 bits in big-endian order

Commit 14180d6221 ("bswap: Add the ability to store to an
unaligned 24 bit field") added st24_le_p() for little
endianness, add st24_be_p() equivalent for bit one.

Signed-off-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Cédric Le Goater <clg@redhat.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20240621075607.17902-1-philmd@linaro.org>