gm45 boards: Factor out MAX_CPUS

The gm45 northbridge supports at most 4 threads. However, the only two
mobile Core 2 Quad models are not BGA956, so account for that as well.

Change-Id: Ie198ac4c366ec0bd53ddb337b6f9c03c331c73f5
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/41844
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>

src/cpu/intel/socket_BGA956/Kconfig

@@ -18,4 +18,8 @@ config DCACHE_BSP_STACK_SIZE
 	hex
 	default 0x2000
 
+config MAX_CPUS
+	int
+	default 2
+
 endif

src/cpu/intel/socket_p/Kconfig

@@ -19,4 +19,8 @@ config DCACHE_BSP_STACK_SIZE
 	hex
 	default 0x2000
 
+config MAX_CPUS
+	int
+	default 4
+
 endif

src/mainboard/lenovo/t400/Kconfig

@@ -71,10 +71,6 @@ config USBDEBUG_HCD_INDEX
 	int
 	default 2
 
-config MAX_CPUS
-	int
-	default 4
-
 config CBFS_SIZE
 	hex
 	default 0x200000

src/mainboard/lenovo/x200/Kconfig

@@ -64,10 +64,6 @@ config USBDEBUG_HCD_INDEX
 	int
 	default 2
 
-config MAX_CPUS
-	int
-	default 2
-
 config CBFS_SIZE
 	hex
 	default 0x200000

src/mainboard/roda/rk9/Kconfig

@@ -25,10 +25,6 @@ config MAINBOARD_PART_NUMBER
 	string
 	default "RK9"
 
-config MAX_CPUS
-	int
-	default 2
-
 config CBFS_SIZE
 	hex
 	default ROM_SIZE