rockchip: remove duplicate CONFIG_ENV_SIZE definitions

A few header files still have a definition of CONFIG_ENV_SIZE, causing
warnings during buildman runs.  This removes the duplicate definitions
from evb_px5.h, geekbox.h and rv1108_common.h.

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
diff --git a/include/configs/evb_px5.h b/include/configs/evb_px5.h
index d008539..4160187 100644
--- a/include/configs/evb_px5.h
+++ b/include/configs/evb_px5.h
@@ -9,8 +9,6 @@
 
 #include <configs/rk3368_common.h>
 
-#define CONFIG_ENV_SIZE			0x2000
-
 #define CONFIG_CONSOLE_SCROLL_LINES	10
 
 #endif
diff --git a/include/configs/geekbox.h b/include/configs/geekbox.h
index 7a707cb..bb2ef9a 100644
--- a/include/configs/geekbox.h
+++ b/include/configs/geekbox.h
@@ -9,8 +9,6 @@
 
 #include <configs/rk3368_common.h>
 
-#define CONFIG_ENV_SIZE			0x2000
-
 #define CONFIG_CONSOLE_SCROLL_LINES		10
 
 #endif
diff --git a/include/configs/rv1108_common.h b/include/configs/rv1108_common.h
index 5ee4559..549839d 100644
--- a/include/configs/rv1108_common.h
+++ b/include/configs/rv1108_common.h
@@ -9,7 +9,6 @@
 #include <asm/arch/hardware.h>
 #include "rockchip-common.h"
 
-#define CONFIG_ENV_SIZE			0x2000
 #define CONFIG_SYS_MALLOC_LEN		(32 << 20)
 #define CONFIG_SYS_CBSIZE		1024
 #define CONFIG_SKIP_LOWLEVEL_INIT