ARM: at91: ddr: remove CONFIG_SOC_SAMA7 dependency

[ Upstream commit dc300570

 ]

Remove CONFIG_SOC_SAMA7 dependency to avoid having #ifdef preprocessor
directives in driver code (arch/arm/mach-at91/pm.c). This prepares the
code for next commits.

Signed-off-by: Claudiu Beznea <claudiu.beznea@microchip.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Link: https://lore.kernel.org/r/20220113144900.906370-2-claudiu.beznea@microchip.com
Signed-off-by: Sasha Levin <sashal@kernel.org>