Replace deprecated "ramdisk" with "ramdisk_size" kernel parameter.

The Linux commit fac8b209b1084bc85748bd54e13d00c1262b220f ("Remove
final traces of long-deprecated "ramdisk" kernel parm") makes these
changes neccessary.

Signed-off-by: Detlev Zundel <dzu@denx.de>
diff --git a/include/configs/AmigaOneG3SE.h b/include/configs/AmigaOneG3SE.h
index d914dcc..a992498 100644
--- a/include/configs/AmigaOneG3SE.h
+++ b/include/configs/AmigaOneG3SE.h
@@ -54,7 +54,7 @@
 
 #undef CONFIG_CLOCKS_IN_MHZ		/* clocks passed to Linux in Hz */
 
-#define CONFIG_BOOTARGS		"root=/dev/ram rw ramdisk=4096"
+#define CONFIG_BOOTARGS		"root=/dev/ram rw ramdisk_size=4096"
 
 /*
  * BOOTP options