rtc: pcf2127: Update Kconfig and code style

Unfortunately version 2 of this patch was applied which was missing some
changes. Fix this.

Signed-off-by: Meng Yi <meng.yi@nxp.com>
Acked-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/rtc/Kconfig b/drivers/rtc/Kconfig
index 57af1b5..cb79a01 100644
--- a/drivers/rtc/Kconfig
+++ b/drivers/rtc/Kconfig
@@ -17,6 +17,10 @@
 	bool "Enable PCF2127 driver"
 	depends on DM_RTC
 	help
-	  Enable pcf2127 driver which provides rtc get and set function
+	  The PCF2127 is a CMOS Real Time Clock (RTC) and calendar with an integrated
+	  Temperature Compensated Crystal (Xtal) Oscillator (TCXO) and a 32.768 kHz quartz
+	  crystal optimized for very high accuracy and very low power consumption. The PCF2127
+	  has a selectable I2C-bus or SPI-bus, a backup battery switch-over circuit, a
+	  programmable watchdog function, a timestamp function, and many other features.
 
 endmenu