RGBDS syntax updates (#905)

New MACRO and DEF syntax

maps/CeladonDeptStore6F.asm

@@ -1,6 +1,6 @@
-CELADONDEPTSTORE6F_FRESH_WATER_PRICE EQU 200
-CELADONDEPTSTORE6F_SODA_POP_PRICE    EQU 300
-CELADONDEPTSTORE6F_LEMONADE_PRICE    EQU 350
+DEF CELADONDEPTSTORE6F_FRESH_WATER_PRICE EQU 200
+DEF CELADONDEPTSTORE6F_SODA_POP_PRICE    EQU 300
+DEF CELADONDEPTSTORE6F_LEMONADE_PRICE    EQU 350
 
 	object_const_def
 	const CELADONDEPTSTORE6F_SUPER_NERD