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>

src/flash/nor/sim3x.c

@@ -748,7 +748,7 @@ static int sim3x_read_info(struct flash_bank *bank)
 	}
 
 	if (((cpuid >> 4) & 0xfff) != 0xc23) {
-		LOG_ERROR("Target is not CortexM3");
+		LOG_ERROR("Target is not Cortex-M3");
 		return ERROR_FAIL;
 	}
 
@@ -1009,7 +1009,7 @@ COMMAND_HANDLER(sim3x_lock)
 			return ret;
 
 		if ((val & CPUID_CHECK_VALUE_MASK) != CPUID_CHECK_VALUE) {
-			LOG_ERROR("Target is not ARM CortexM3 or is already locked");
+			LOG_ERROR("Target is not ARM Cortex-M3 or is already locked");
 			return ERROR_FAIL;
 		}
 	} else {