Replace magic numbers with BANK_COUNT_* constants

Previously, some instances of the number of banks for each section remained hardcoded. These have been replaced with BANK_COUNT_* constants.

As a side-effect, this could fix a theoretical bug when using BANK(label) when the label is in a high SRAM bank (≥ 4).

include/link/assign.h

@@ -3,16 +3,6 @@
 
 #include "types.h"
 
-enum eBankDefine {
-	BANK_ROM0 = 0,
-	BANK_ROMX,
-	BANK_WRAM0 = 512,
-	BANK_WRAMX,
-	BANK_VRAM = 520,
-	BANK_HRAM = 522,
-	BANK_SRAM = 523
-};
-
 enum eBankCount {
 	BANK_COUNT_ROM0 = 1,
 	BANK_COUNT_ROMX = 511,
@@ -23,6 +13,16 @@ enum eBankCount {
 	BANK_COUNT_SRAM = 16
 };
 
+enum eBankDefine {
+	BANK_ROM0  = 0,
+	BANK_ROMX  = BANK_ROM0  + BANK_COUNT_ROM0,
+	BANK_WRAM0 = BANK_ROMX  + BANK_COUNT_ROMX,
+	BANK_WRAMX = BANK_WRAM0 + BANK_COUNT_WRAM0,
+	BANK_VRAM  = BANK_WRAMX + BANK_COUNT_WRAMX,
+	BANK_HRAM  = BANK_VRAM  + BANK_COUNT_VRAM,
+	BANK_SRAM  = BANK_HRAM  + BANK_COUNT_HRAM
+};
+
 #define MAXBANKS	(BANK_COUNT_ROM0 + BANK_COUNT_ROMX + BANK_COUNT_WRAM0 + BANK_COUNT_WRAMX \
 					+ BANK_COUNT_VRAM + BANK_COUNT_HRAM + BANK_COUNT_SRAM)