flash/nor: add support for TI MSP432 devices

Added msp432 flash driver to support the TI MSP432P4x and
MSP432E4x microcontrollers. Implemented the flash algo
helper as used in the TI debug and flash tools. This
implemention supports the MSP432E4, Falcon, and Falcon 2M
variants. The flash driver automatically detects the
connected variant and configures itself appropriately.
Added command to mass erase device for consistency with
TI tools and added command to unlock the protected BSL
region.

Tested using MSP432E401Y, MSP432P401R, and MSP432P4111
LaunchPads.
Tested with embedded XDS110 debug probe in CMSIS-DAP
mode and with external SEGGER J-Link probe.

Removed ti_msp432p4xx.cfg file made obsolete by this
patch.
Change-Id: I3b29d39ccc492524ef2c4a1733f7f9942c2684c0
Signed-off-by: Edward Fewell <efewell@ti.com>
Reviewed-on: http://openocd.zylin.com/4153
Tested-by: jenkins
Reviewed-by: Matthias Welwarsky <matthias@welwarsky.de>
Reviewed-by: Tomas Vanek <vanekt@fbl.cz>

tcl/target/ti_msp432.cfg

@@ -1,5 +1,5 @@
 #
-# Texas Instruments MSP432P4xx - ARM Cortex-M4F @ up to 48 MHz
+# Texas Instruments MSP432 - ARM Cortex-M4F @ up to 48 MHz
 #
 # http://www.ti.com/MSP432
 #
@@ -7,7 +7,7 @@
 if { [info exists CHIPNAME] } {
 	set _CHIPNAME $CHIPNAME
 } else {
-	set _CHIPNAME msp432p4xx
+	set _CHIPNAME msp432
 }
 
 if { [info exists CPUTAPID] } {
@@ -39,15 +39,13 @@ target create $_TARGETNAME cortex_m -dap $_CHIPNAME.dap
 if { [info exists WORKAREASIZE] } {
 	set _WORKAREASIZE $WORKAREASIZE
 } else {
-	# On MSP432P401x Bank0 (8k) is always powered
-	set _WORKAREASIZE 0x2000
+	set _WORKAREASIZE 0x4000
 }
 
-$_TARGETNAME configure -work-area-phys 0x20000000 \
-                       -work-area-size $_WORKAREASIZE -work-area-backup 0
+$_TARGETNAME configure -work-area-phys 0x20000000 -work-area-size $_WORKAREASIZE -work-area-backup 0
 
-if { ![using_hla] } {
-	cortex_m reset_config sysresetreq
-}
+set _FLASHNAME $_CHIPNAME.flash
+flash bank $_FLASHNAME msp432 0 0 0 0 $_TARGETNAME
 
-adapter_khz 500
+reset_config srst_only
+adapter_nsrst_delay 100