gpio: Fix wrong rounding in gpio-menz127

gpio: Fix wrong rounding in gpio-menz127

BugLink: https://bugs.launchpad.net/bugs/1836287
[ Upstream commit 7279d9917560bbd0d82813d6bf00490a82c06783 ]

men_z127_debounce() tries to round up and down, but uses functions which
are only suitable when the divider is a power of two, which is not the
case. Use the appropriate ones.

Found by static check. Compile tested.

Fixes: f436bc2726c64 ("gpio: add driver for MEN 16Z127 GPIO controller")
Signed-off-by: Nadav Amit <namit@vmware.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sasha Levin <alexander.levin@microsoft.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>