thermal: intel: BXT_PMIC: select REGMAP instead of depending on it

REGMAP is a hidden (not user visible) symbol. Users cannot set it
directly thru "make *config", so drivers should select it instead of
depending on it if they need it.

Consistently using "select" or "depends on" can also help reduce
Kconfig circular dependency issues.

Therefore, change the use of "depends on REGMAP" to "select REGMAP".

Fixes: b474303 ("thermal: add Intel BXT WhiskeyCove PMIC thermal driver")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/thermal/intel/Kconfig

@@ -73,7 +73,8 @@ endmenu
 
 config INTEL_BXT_PMIC_THERMAL
 	tristate "Intel Broxton PMIC thermal driver"
-	depends on X86 && INTEL_SOC_PMIC_BXTWC && REGMAP
+	depends on X86 && INTEL_SOC_PMIC_BXTWC
+	select REGMAP
 	help
 	  Select this driver for Intel Broxton PMIC with ADC channels monitoring
 	  system temperature measurements and alerts.