lenovo/t500: Add clone of Lenovo T400

The existing code for the Lenovo T400 works without changes on the
Lenovo T500.  Same HDA verbs are provided by Lenovo BIOS on both
laptops.

Change-Id: I300408a8a0ed00476aee6061925befc2822fb505
Signed-off-by: Francis Rowe <info@gluglug.org.uk>
Reviewed-on: https://review.coreboot.org/10545
Tested-by: build bot (Jenkins)
Reviewed-by: Nico Huber <nico.h@gmx.de>
Reviewed-by: Martin Roth <martinroth@google.com>

src/mainboard/lenovo/t400/Kconfig

@@ -1,4 +1,4 @@
-if BOARD_LENOVO_T400 || BOARD_LENOVO_R400
+if BOARD_LENOVO_T400 || BOARD_LENOVO_T500 || BOARD_LENOVO_R400
 
 config BOARD_SPECIFIC_OPTIONS # dummy
 	def_bool y

src/mainboard/lenovo/t500/Kconfig

@@ -0,0 +1,7 @@
+if BOARD_LENOVO_T500
+
+config MAINBOARD_PART_NUMBER
+	string
+	default "ThinkPad T500"
+
+endif

src/mainboard/lenovo/t500/Kconfig.name

@@ -0,0 +1,2 @@
+config BOARD_LENOVO_T500
+	bool "ThinkPad T500"

src/mainboard/lenovo/t500/board_info.txt

@@ -0,0 +1,6 @@
+Category: laptop
+ROM package: SOIC-16 or SOIC-8
+ROM protocol: SPI
+ROM socketed: n
+Flashrom support: n
+Clone of: lenovo/t400