8051: Allow up to 64KB firmware images.

The ITE EC hardware always has the first 32KB of ram mapped, while
a second 32KB of ram is banked immediately after. By default, the
banked physical address immediately follows the fixed area in flash.

src/ec/it5570e/ec.mk

@@ -2,6 +2,9 @@
 
 ARCH=8051
 
+# 64 KB is the max without banking
+CODE_SIZE=65536
+
 # SRAM is 6144 bytes, only 4096 bytes are mapped at address 0. Region at
 # 0x0E00-0x1000 is used for AP communication. So this is brought down to 2048,
 # which matches it8587e limits

src/ec/it8587e/ec.mk

@@ -2,5 +2,8 @@
 
 ARCH=8051
 
+# 64 KB is the max without banking
+CODE_SIZE=65536
+
 # SRAM is 4096 bytes, but SRAM at address 2048 is used for scratch ROM
 SRAM_SIZE=2048