cpu/intel: Rename socket_mPGA478MN to socket_p

These marketing names are much easier to distinguish. My
mnemonic: Socket M => up to Merom, Socket P => up to Penryn.

Change-Id: I3c2a59596cf7f3cd763bd79962ad326ab080677b
Signed-off-by: Nico Huber <nico.huber@secunet.com>
Reviewed-on: https://review.coreboot.org/c/31645
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
diff --git a/src/mainboard/lenovo/t400/Kconfig b/src/mainboard/lenovo/t400/Kconfig
index ab5818f..57e31f2 100644
--- a/src/mainboard/lenovo/t400/Kconfig
+++ b/src/mainboard/lenovo/t400/Kconfig
@@ -4,7 +4,7 @@
 config BOARD_SPECIFIC_OPTIONS
 	def_bool y
 	select SYSTEM_TYPE_LAPTOP
-	select CPU_INTEL_SOCKET_MPGA478MN
+	select CPU_INTEL_SOCKET_P
 	select NORTHBRIDGE_INTEL_GM45
 	select SOUTHBRIDGE_INTEL_I82801IX
 	select EC_LENOVO_PMH7