km83xx: use CONFIG_ENV_ADDR for the newenv env command

The hardcoded value are bad, since the address could change between
different boards.

Furthermore, the relevant #defines are set only if #undefined here, so
that they can be changed by some boards if required.
Signed-off-by: NValentin Longchamp <valentin.longchamp@keymile.com>

include/configs/km/km83xx-common.h

@@ -181,10 +181,14 @@
 
 #ifndef CONFIG_SYS_RAMBOOT
 #define CONFIG_ENV_IS_IN_FLASH
+#ifndef CONFIG_ENV_ADDR
 #define CONFIG_ENV_ADDR		(CONFIG_SYS_MONITOR_BASE + \
 					CONFIG_SYS_MONITOR_LEN)
+#endif
 #define CONFIG_ENV_SECT_SIZE	0x20000 /* 128K(one sector) for env */
+#ifndef CONFIG_ENV_OFFSET
 #define CONFIG_ENV_OFFSET	(CONFIG_SYS_MONITOR_LEN)
+#endif
 
 /* Address and size of Redundant Environment Sector	*/
 #define CONFIG_ENV_OFFSET_REDUND	(CONFIG_ENV_OFFSET + \
@@ -319,8 +323,8 @@
 	CONFIG_KM_DEF_ENV						\
 	CONFIG_KM_DEF_ARCH						\
 	"newenv="							\
-		"prot off 0xF00C0000 +0x40000 && "			\
-		"era 0xF00C0000 +0x40000\0"				\
+		"prot off "__stringify(CONFIG_ENV_ADDR)" +0x40000 && "	\
+		"era "__stringify(CONFIG_ENV_ADDR)" +0x40000\0"		\
 	"unlock=yes\0"							\
 	""