rtc: ds1307: simplify hwmon config

We don't have to define an extra config symbol, IS_REACHABLE does
what we need. And having this config symbol just to save the few
bytes of hwmon support on non-DS3231 chips isn't worth it IMO
(especially as the symbol is set per default).
Signed-off-by: Heiner Kallweit <hkallweit1@gmail.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>

drivers/rtc/Kconfig

@@ -244,15 +244,6 @@ config RTC_DRV_DS1307
 	  This driver can also be built as a module. If so, the module
 	  will be called rtc-ds1307.
 
-config RTC_DRV_DS1307_HWMON
-	bool "HWMON support for rtc-ds1307"
-	depends on RTC_DRV_DS1307 && HWMON
-	depends on !(RTC_DRV_DS1307=y && HWMON=m)
-	default y
-	help
-	  Say Y here if you want to expose temperature sensor data on
-	  rtc-ds1307 (only DS3231)
-
 config RTC_DRV_DS1307_CENTURY
 	bool "Century bit support for rtc-ds1307"
 	depends on RTC_DRV_DS1307

drivers/rtc/rtc-ds1307.c

@@ -1042,7 +1042,7 @@ static u8 ds1307_trickle_init(struct ds1307 *ds1307,
 
 /*----------------------------------------------------------------------*/
 
-#ifdef CONFIG_RTC_DRV_DS1307_HWMON
+#if IS_REACHABLE(CONFIG_HWMON)
 
 /*
  * Temperature sensor support for ds3231 devices.