lpc1768.cfg pulled out constants from flash init as variables

Seems like an esthetic change, but it will allow easy support for
other lpc17xx devices.

Change-Id: I2cb953ce1afdd82f6ca65b38d5557a28416f895e
Signed-off-by: Vandra Akos <axos88@gmail.com>
Reviewed-on: http://openocd.zylin.com/674
Tested-by: jenkins
Reviewed-by: Spencer Oliver <spen@spen-soft.co.uk>

tcl/target/lpc1768.cfg

@@ -22,12 +22,25 @@ if { [info exists CCLK] } {
 } else {
 	set _CCLK 4000
 }
+
 if { [info exists CPUTAPID] } {
 	set _CPUTAPID $CPUTAPID
 } else {
 	set _CPUTAPID 0x4ba00477
 }
 
+if { [info exists CPURAMSIZE] } {
+  set _CPURAMSIZE $CPURAMSIZE
+} else {
+  set _CPURAMSIZE 0x8000
+}
+
+if { [info exists CPUROMSIZE] } {
+  set _CPUROMSIZE $CPUROMSIZE
+} else {
+  set _CPUROMSIZE 0x80000
+}
+
 #delays on reset lines
 adapter_nsrst_delay 200
 jtag_ntrst_delay 200
@@ -40,13 +53,13 @@ target create $_TARGETNAME cortex_m3 -chain-position $_TARGETNAME
 
 # LPC1768 has 32kB of SRAM In the ARMv7-M "Code" area (at 0x10000000)
 # and 32K more on AHB, in the ARMv7-M "SRAM" area, (at 0x2007c000).
-$_TARGETNAME configure -work-area-phys 0x10000000 -work-area-size 0x8000
+$_TARGETNAME configure -work-area-phys 0x10000000 -work-area-size $_CPURAMSIZE
 
 # LPC1768 has 512kB of flash memory, managed by ROM code (including a
 # boot loader which verifies the flash exception table's checksum).
 # flash bank <name> lpc2000 <base> <size> 0 0 <target#> <variant> <clock> [calc checksum]
 set _FLASHNAME $_CHIPNAME.flash
-flash bank $_FLASHNAME lpc2000 0x0 0x80000 0 0 $_TARGETNAME \
+flash bank $_FLASHNAME lpc2000 0x0 $_CPUROMSIZE 0 0 $_TARGETNAME \
 	lpc1700 $_CCLK calc_checksum
 
 # Run with *real slow* clock by default since the