Fix spelling of ARM Cortex

It's Cortex-Xn, not Cortex Xn or cortex xn or cortex-xn or CORTEX-Xn
or CortexXn. Further it's Cortex-M0+, not M0plus.

Cf. http://www.arm.com/products/processors/index.php

Consistently write it the official way, so that it stops propagating.
Originally spotted in the documentation, it mainly affects code comments
but also Atmel SAM3/SAM4/SAMV, NiietCM4 and SiM3x flash driver output.

Found via:

  git grep -i "Cortex "
  git grep -i "Cortex-" | grep -v "Cortex-" | grep -v ".cpu"
  git grep -i "CortexM"

Change-Id: Ic7b6ca85253e027f6f0f751c628d1a2a391fe914
Signed-off-by: Andreas Färber <afaerber@suse.de>
Reviewed-on: http://openocd.zylin.com/3483
Tested-by: jenkins
Reviewed-by: Marc Schink <openocd-dev@marcschink.de>
Reviewed-by: Andreas Fritiofson <andreas.fritiofson@gmail.com>

tcl/target/ti_tms570.cfg

@@ -53,7 +53,7 @@ jtag newtap $_CHIPNAME jrc -irlen 6 -ircapture 0x1 -irmask 0x3f \
 jtag configure $_CHIPNAME.jrc -event setup "jtag tapenable $_CHIPNAME.dap"
 jtag configure $_CHIPNAME.jrc -event post-reset "runtest 100"
 
-# Cortex R4 target
+# Cortex-R4 target
 set _TARGETNAME $_CHIPNAME.cpu
 target create $_TARGETNAME cortex_r4 -endian $_ENDIAN \
 	-chain-position $_CHIPNAME.dap -coreid 0 -dbgbase 0x00001003