ARM: rmobile: Rework the ULCB CPLD driver

Rework the ULCB CPLD driver and make it into a sysreset driver,
since that is what the ULCB CPLD driver is mostly for.

Signed-off-by: Marek Vasut <marek.vasut+renesas@gmail.com>
Cc: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
diff --git a/configs/r8a7795_ulcb_defconfig b/configs/r8a7795_ulcb_defconfig
index 75316d7..0959bb4 100644
--- a/configs/r8a7795_ulcb_defconfig
+++ b/configs/r8a7795_ulcb_defconfig
@@ -47,6 +47,7 @@
 CONFIG_DM_REGULATOR_FIXED=y
 CONFIG_DM_REGULATOR_GPIO=y
 CONFIG_SCIF_CONSOLE=y
+CONFIG_SYSRESET=y
 CONFIG_USB=y
 CONFIG_DM_USB=y
 CONFIG_USB_XHCI_HCD=y