Move baytrail & fsp_baytrail to the common IFD interface.

- Add the common/firmware subdir to the baytrail & fsp_baytrail
makefiles and remove the code it replaces.
- Update baytrail & fsp_baytrail Kconfigs to use the common code.
- Update the IFD Kconfig help and prompts for the TXE vs ME.
- Whittle away at the CBFS_SIZE defaults.  All the fsp_baytrail
platforms have their own defaults.

Change-Id: I96a9d4acd6578225698dba28d132d203b8fb71a0
Signed-off-by: Martin Roth <gaumless@gmail.com>
Reviewed-on: http://review.coreboot.org/10647
Tested-by: build bot (Jenkins)
Reviewed-by: Werner Zeh <werner.zeh@siemens.com>
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
diff --git a/src/southbridge/intel/common/firmware/Kconfig b/src/southbridge/intel/common/firmware/Kconfig
index 71434ac..8ad1fed 100644
--- a/src/southbridge/intel/common/firmware/Kconfig
+++ b/src/southbridge/intel/common/firmware/Kconfig
@@ -38,15 +38,17 @@
 	depends on HAVE_IFD_BIN && !BUILD_WITH_FAKE_IFD
 
 config HAVE_ME_BIN
-	bool "Add Intel Management Engine firmware"
+	bool "Add Intel ME/TXE firmware"
 	depends on HAVE_IFD_BIN
 	help
 	  The Intel processor in the selected system requires a special firmware
-	  for an integrated controller called Management Engine (ME). The ME
-	  firmware might be provided in coreboot's 3rdparty/blobs repository. If
-	  not and if you don't have the firmware elsewhere, you can still
-	  build coreboot without it. In this case however, you'll have to make
-	  sure that you don't overwrite your ME firmware on your flash ROM.
+	  for an integrated controller.  This might be called the Management
+	  Engine (ME), the Trusted Execution Engine (TXE) or something else
+	  depending on the chip. This firmware might or might not be available
+	  in coreboot's 3rdparty/blobs repository. If it is not and if you don't
+	  have access to the firmware from elsewhere, you can still build
+	  coreboot without it. In this case however, you'll have to make sure
+	  that you don't overwrite your ME/TXE firmware on your flash ROM.
 
 config ME_BIN_PATH
 	string "Path to management engine firmware"