y2038: make do_gettimeofday() and get_seconds() inline

y2038: make do_gettimeofday() and get_seconds() inline

BugLink: https://bugs.launchpad.net/bugs/1853915
[ Upstream commit 33e26418193f58d1895f2f968e1953b1caf8deb7 ]

get_seconds() and do_gettimeofday() are only used by a few modules now any
more (waiting for the respective patches to get accepted), and they are
among the last holdouts of code that is not y2038 safe in the core kernel.

Move the implementation into the timekeeping32.h header to clean up
the core kernel and isolate the old interfaces further.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Khalid Elmously <khalid.elmously@canonical.com>