soc/intel/skylake: Add NHLT config for max98373 codec

Add the NHLT configuration for the max98373 codec to skylake,
taken directly from cannonlake.

This will allow skylake/kabylake boards to use this codec.

Change-Id: Ifb6bf2d31fda25b18d9b1ce2bb721255335d55e4
Signed-off-by: Duncan Laurie <dlaurie@google.com>
Reviewed-on: https://review.coreboot.org/25367
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>
Reviewed-by: HARSHAPRIYA N <harshapriya.n@intel.com>
Reviewed-by: Sathyanarayana Nujella <sathyanarayana.nujella@intel.com>

src/soc/intel/skylake/Kconfig

@@ -253,6 +253,12 @@ config NHLT_MAX98357
 	help
 	  Include DSP firmware settings for max98357 amplifier.
 
+config NHLT_MAX98373
+	bool
+	default n
+	help
+	  Include DSP firmware settings for max98373 amplifier.
+
 config NHLT_SSM4567
 	bool
 	default n