expand parameter area for ArduPlane

this ensures all parameters can be saved without overflow

ArduPlane/defines.h

@@ -200,8 +200,8 @@ enum gcs_severity {
 
 // EEPROM addresses
 #define EEPROM_MAX_ADDR		4096
-// parameters get the first 1KiB of EEPROM, remainder is for waypoints
-#define WP_START_BYTE 0x400 // where in memory home WP is stored + all other WP
+// parameters get the first 1280 of EEPROM, remainder is for waypoints
+#define WP_START_BYTE 0x500 // where in memory home WP is stored + all other WP
 #define WP_SIZE 15
 
 // fence points are stored at the end of the EEPROM