nb/intel/nehalem: Rename to ironlake

The code is for Arrandale CPUs, whose System Agent is Ironlake.

This change simply replaces `nehalem` with `ironlake` and `NEHALEM`
with `IRONLAKE`. The remaining `Nehalem` cases are handled later, as
changing some of them would impact the resulting binary.

Tested with BUILD_TIMELESS=1 without adding the configuration options
into the binary, and packardbell/ms2290 does not change.

Change-Id: I8eb96eeb5e69f49150d47793b33e87b650c64acc
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/38941
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
Reviewed-by: Martin Roth <martinroth@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/cpu/x86/Kconfig b/src/cpu/x86/Kconfig
index dd7bb30..4260278 100644
--- a/src/cpu/x86/Kconfig
+++ b/src/cpu/x86/Kconfig
@@ -140,7 +140,7 @@
 	bool
 	default y if NORTHBRIDGE_INTEL_I945
 	default y if NORTHBRIDGE_INTEL_GM45
-	default y if NORTHBRIDGE_INTEL_NEHALEM
+	default y if NORTHBRIDGE_INTEL_IRONLAKE
 	default n
 
 config SERIALIZED_SMM_INITIALIZATION