Make the lpc2xxx generic driver support romless parts

tcl/target/lpc2xxx.cfg

@@ -29,9 +29,11 @@ proc setup_lpc2xxx {chip_name cputapids flash_size flash_variant workarea_size c
 	
 	$_TARGETNAME configure -work-area-phys 0x40000000 -work-area-size $workarea_size -work-area-backup 0
 	
-	# flash bank <name> lpc2000 <base> <size> 0 0 <target#> <variant> <clock> [calc checksum]
-	set _FLASHNAME $chip_name.flash
-	flash bank $_FLASHNAME lpc2000 0x0 $flash_size 0 0 $_TARGETNAME $flash_variant $core_freq_khz calc_checksum
+	if { $flash_size > 0 } {
+		# flash bank <name> lpc2000 <base> <size> 0 0 <target#> <variant> <clock> [calc checksum]
+		set _FLASHNAME $chip_name.flash
+		flash bank $_FLASHNAME lpc2000 0x0 $flash_size 0 0 $_TARGETNAME $flash_variant $core_freq_khz calc_checksum
+	}
 }
 
 proc init_targets {} {