[ Upstream commit a49cc1fe9d64a2dc4e19b599204f403e5d25f44b ] Implements atomic transfers to fix reboot/shutdown on r8a7790 Lager and similar boards. Signed-off-by: Ulrich Hecht <uli+renesas@fpond.eu> Tested-by: Wolfram Sang <wsa+renesas@sang-engineering.com> Tested-by: Geert Uytterhoeven <geert+renesas@glider.be> [wsa: some whitespace fixing] Signed-off-by: Wolfram Sang <wsa@kernel.org> Signed-off-by: Sasha Levin <sashal@kernel.org>