bootcount: add a DM i2c eeprom backing store for bootcount

This driver allows the use of i2c eeprom device or partition as backing
store for boot counter values with DM enabled.

Signed-off-by: Robert Beckett <bob.beckett@collabora.com>
diff --git a/drivers/bootcount/Makefile b/drivers/bootcount/Makefile
index f9841d8..73ccfb5 100644
--- a/drivers/bootcount/Makefile
+++ b/drivers/bootcount/Makefile
@@ -10,3 +10,4 @@
 
 obj-$(CONFIG_DM_BOOTCOUNT)      += bootcount-uclass.o
 obj-$(CONFIG_DM_BOOTCOUNT_RTC)  += rtc.o
+obj-$(CONFIG_DM_BOOTCOUNT_I2C_EEPROM)	+= i2c-eeprom.o