host-utils: Add muldiv64_round_up

host-utils: Add muldiv64_round_up

This will be used for converting time intervals in different base units
to host units, for the purpose of scheduling timers to emulate target
timers. Timers typically must not fire before their requested expiry
time but may fire some time afterward, so rounding up is the right way
to implement these.

Signed-off-by: Nicholas Piggin <npiggin@gmail.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
[ clg: renamed __muldiv64() to muldiv64_rounding() ]
Signed-off-by: Cédric Le Goater <clg@kaod.org>
(cherry picked from commit 47de6c4c287079744ceb96f606b3c0457addf380)
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>