Convert CONFIG_BOOTCOUNT_AM33XX to Kconfig

This converts the following to Kconfig:
  CONFIG_BOOTCOUNT_AM33XX

Reviewed-by: Lukasz Majewski <lukma@denx.de>
Reviewed-by: Hannes Schmelzer <hannes.schmelzer@br-automation.com>
Acked-by: Hannes Schmelzer <hannes.schmelzer@br-automation.com>
Signed-off-by: Alex Kiernan <alex.kiernan@gmail.com>
diff --git a/drivers/bootcount/Kconfig b/drivers/bootcount/Kconfig
index 26fec89..e905295 100644
--- a/drivers/bootcount/Kconfig
+++ b/drivers/bootcount/Kconfig
@@ -12,6 +12,7 @@
 
 choice
 	prompt "Boot count device"
+	default BOOTCOUNT_AM33XX if AM33XX || SOC_DA8XX
 
 config BOOTCOUNT_EXT
 	bool "Boot counter on EXT filesystem"
@@ -19,6 +20,14 @@
 	  Add support for maintaining boot count in a file on an EXT
 	  filesystem.
 
+config BOOTCOUNT_AM33XX
+	bool "Boot counter in AM33XX RTC IP block"
+	depends on AM33XX || SOC_DA8XX
+	help
+	  A bootcount driver for the RTC IP block found on many TI platforms.
+	  This requires the RTC clocks, etc, to be enabled prior to use and
+	  not all boards with this IP block on it will have the RTC in use.
+
 endchoice
 
 config SYS_BOOTCOUNT_SINGLEWORD