rtc: Kconfig: select REGMAP_I2C when necessary

[ Upstream commit 578c2b6 ]

Some i2c RTC drivers are using regmap but are not selecting REGMAP_I2C
which may lead to build failures.

Link: https://lore.kernel.org/r/20200127221724.10160-2-alexandre.belloni@bootlin.com
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>

drivers/rtc/Kconfig

@@ -240,6 +240,7 @@ config RTC_DRV_AS3722
 
 config RTC_DRV_DS1307
 	tristate "Dallas/Maxim DS1307/37/38/39/40/41, ST M41T00, EPSON RX-8025, ISL12057"
+	select REGMAP_I2C
 	help
 	  If you say yes here you get support for various compatible RTC
 	  chips (often with battery backup) connected with I2C. This driver
@@ -632,6 +633,7 @@ config RTC_DRV_RX8010
 
 config RTC_DRV_RX8581
 	tristate "Epson RX-8571/RX-8581"
+	select REGMAP_I2C
 	help
 	  If you say yes here you will get support for the Epson RX-8571/
 	  RX-8581.
@@ -659,6 +661,7 @@ config RTC_DRV_EM3027
 
 config RTC_DRV_RV3028
 	tristate "Micro Crystal RV3028"
+	select REGMAP_I2C
 	help
 	  If you say yes here you get support for the Micro Crystal
 	  RV3028.
@@ -688,6 +691,7 @@ config RTC_DRV_S5M
 
 config RTC_DRV_SD3078
     tristate "ZXW Shenzhen whwave SD3078"
+    select REGMAP_I2C
     help
       If you say yes here you get support for the ZXW Shenzhen whwave
       SD3078 RTC chips.