treewide: Replace uses of "Nehalem"

The code in coreboot is actually for the Arrandale processors, which
are a MCM (Multi-Chip Module) with two different dies:

- Hillel:   32nm Westmere dual-core CPU
- Ironlake: 45nm northbridge with integrated graphics

This has nothing to do with the older, single-die Nehalem processors.
Therefore, replace the references to Nehalem with the correct names.

Change-Id: I8c10a2618c519d2411211b9b8f66d24f0018f908
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/38942
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/drivers/intel/gma/Kconfig

@@ -39,7 +39,7 @@ config INTEL_GMA_SSC_ALTERNATE_REF
 	  To be set by northbridge or mainboard Kconfig.  For most platforms,
 	  there is no choice, i.e. for i945 and gm45 the SSC reference always
 	  differs from the display reference clock (i945: 66Mhz SSC vs. 48MHz
-	  DREF; gm45: 100MHz SSC vs. 96Mhz DREF), for Nehalem and newer, it's
+	  DREF; gm45: 100MHz SSC vs. 96Mhz DREF), for Arrandale and newer, it's
 	  the same frequency for SSC/non-SSC (120MHz).  The only, currently
 	  supported platform with a choice seems to be Pineview, where the
 	  alternative is 100MHz vs. the default 96MHz.