cmd: Kconfig: Change dependency for CMD_ADC

CMD_ADC selected DM_REGULATOR unconditionally without enabling DM.
That's why change select to depends on to cover it.

Kconfig is showing this issue as:
WARNING: unmet direct dependencies detected for REGMAP
  Depends on [n]: DM [=n]
  Selected by [y]:
  - DM_REGULATOR_PBIAS [=y] && DM_REGULATOR [=y]

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Reviewed-by: Tom Rini <trini@konsulko.com>
[trini: Update CMD_ADC=y configs to enable DM_REGULATOR now]
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/cmd/Kconfig b/cmd/Kconfig
index 30c26b5..0761dbb 100644
--- a/cmd/Kconfig
+++ b/cmd/Kconfig
@@ -860,7 +860,7 @@
 config CMD_ADC
 	bool "adc - Access Analog to Digital Converters info and data"
 	select ADC
-	select DM_REGULATOR
+	depends on DM_REGULATOR
 	help
 	  Shows ADC device info and permit printing one-shot analog converted
 	  data from a named Analog to Digital Converter.