dm: core: Add SPL Kconfig for REGMAP and SYSCON

Add SPL Kconfig for REGMAP and SYSCON, so REGMAP and SYSCON can
remove from SPL stage.

Signed-off-by: Lin Huang <hl@rock-chips.com>
Acked-by: Simon Glass <sjg@chromium.org>
diff --git a/configs/sandbox_defconfig b/configs/sandbox_defconfig
index fb1b09f..731fc25 100644
--- a/configs/sandbox_defconfig
+++ b/configs/sandbox_defconfig
@@ -22,7 +22,9 @@
 CONFIG_OF_CONTROL=y
 CONFIG_OF_HOSTFILE=y
 CONFIG_REGMAP=y
+CONFIG_SPL_REGMAP=y
 CONFIG_SYSCON=y
+CONFIG_SPL_SYSCON=y
 CONFIG_DEVRES=y
 CONFIG_ADC=y
 CONFIG_ADC_SANDBOX=y