pitx-imx8m: Kconfig: remove KEX_EEP_BOOTCOUNTER

- KEX_EEP_BOOTCOUNTER is defined in Kontron common Kconfig
Signed-off-by: Thomas Schaefer <thomas.schaefer@kontron.com>

board/kontron/pitx-imx8m/Kconfig

@@ -18,8 +18,4 @@ endmenu
 
 source "board/kontron/common/Kconfig"
 
-config KEX_EEP_BOOTCOUNTER
-	bool "KONTRON EEPROM boot counter support"
-	default y	
-
 endif