AMD Geode cpus: apply un-written naming rules

Kconfig directives to select chip drivers for compile literally
match the chip directory names capitalized and underscored.

Rename directories and Kconfig as follows:
   model_lx  -> geode_lx
   model_gx1 -> geode_gx1
   model_gx2 -> geode_gx2

Change-Id: Ib8bf1e758b88f9efed1cf8b11c76b796388e7147
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: http://review.coreboot.org/613
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>

src/mainboard/bcom/winnet100/Kconfig

@@ -21,7 +21,7 @@ if BOARD_BCOM_WINNET100
 config BOARD_SPECIFIC_OPTIONS # dummy
 	def_bool y
 	select ARCH_X86
-	select CPU_AMD_GX1
+	select CPU_AMD_GEODE_GX1
 	select NORTHBRIDGE_AMD_GX1
 	select SOUTHBRIDGE_AMD_CS5530
 	select SUPERIO_NSC_PC97317

src/mainboard/bcom/winnet100/devicetree.cb

@@ -51,6 +51,6 @@ chip northbridge/amd/gx1		# Northbridge
       register "ide1_enable" = "0"	# Not available/needed on this board
     end
   end
-  chip cpu/amd/model_gx1		# CPU
+  chip cpu/amd/geode_gx1		# CPU
   end
 end