soc/intel/common/block: Add Intel common systemagent support

Create common Intel systemagent code.
This code currently contains the SA initialization
required in Bootblock phase, which has the following programming-
* Set PCIEXBAR
* Clear TSEG register
More code will get added up in the subsequent phases.

Change-Id: I6f0c515278f7fd04d407463a1eeb25ba13639f5c
Signed-off-by: Barnali Sarkar <barnali.sarkar@intel.com>
Signed-off-by: Subrata Banik <subrata.banik@intel.com>
Reviewed-on: https://review.coreboot.org/18565
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
diff --git a/src/soc/intel/common/block/systemagent/Kconfig b/src/soc/intel/common/block/systemagent/Kconfig
new file mode 100644
index 0000000..773a56b
--- /dev/null
+++ b/src/soc/intel/common/block/systemagent/Kconfig
@@ -0,0 +1,26 @@
+config SOC_INTEL_COMMON_BLOCK_SA
+	bool
+	help
+	  Intel Processor common System Agent support
+
+config MMCONF_BASE_ADDRESS
+	hex "PCI MMIO Base Address"
+	default 0xe0000000
+
+config SA_PCIEX_LENGTH
+	hex
+	default 0x10000000 if (PCIEX_LENGTH_256MB)
+	default 0x8000000 if (PCIEX_LENGTH_128MB)
+	default 0x4000000 if (PCIEX_LENGTH_64MB)
+	default 0x10000000
+	help
+	  This option allows you to select length of PCIEX region.
+
+config PCIEX_LENGTH_256MB
+	bool "256MB"
+
+config PCIEX_LENGTH_128MB
+	bool "128MB"
+
+config PCIEX_LENGTH_64MB
+	bool "64MB"