ARM: rmobile: Use PRR driver on all Gen3 boards

Mark the PRR as u-boot,dm-pre-reloc in all Gen3 board DTs as it is
needed very early and turn on the CONFIG_SYSCON to allow the PRR
driver to bind as a syscon uclass.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
diff --git a/configs/r8a7796_salvator-x_defconfig b/configs/r8a7796_salvator-x_defconfig
index 4a36469..849c668 100644
--- a/configs/r8a7796_salvator-x_defconfig
+++ b/configs/r8a7796_salvator-x_defconfig
@@ -26,6 +26,8 @@
 CONFIG_CMD_FS_GENERIC=y
 CONFIG_OF_CONTROL=y
 CONFIG_ENV_IS_IN_MMC=y
+CONFIG_REGMAP=y
+CONFIG_SYSCON=y
 CONFIG_CLK=y
 CONFIG_CLK_RENESAS=y
 CONFIG_DM_GPIO=y