i945 boards: Factor out MAX_CPUS

At least one mobile 945 series northbridge supports 4 threads, because
the dual-core Atom 330 CPU supports Hyper-threading. Therefore, we use
that as the default for this chipset.

Change-Id: I899ed1644d9b2da4fc72f09233a421200770110d
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/41845
Reviewed-by: Felix Held <felix-coreboot@felixheld.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/mainboard/asus/p5gc-mx/Kconfig

@@ -26,8 +26,4 @@ config MAINBOARD_PART_NUMBER
 	string
 	default "P5GC-MX"
 
-config MAX_CPUS
-	int
-	default 4 ## 2 may be the chipsets limit
-
 endif # BOARD_ASUS_P5GC_MX

src/mainboard/getac/p470/Kconfig

@@ -34,10 +34,6 @@ config IRQ_SLOT_COUNT
 	int
 	default 18
 
-config MAX_CPUS
-	int
-	default 4
-
 config VGA_BIOS_FILE
 	string
 	default "getac-pci8086,27a2.rom"

src/mainboard/ibase/mb899/Kconfig

@@ -29,10 +29,6 @@ config IRQ_SLOT_COUNT
 	int
 	default 18
 
-config MAX_CPUS
-	int
-	default 4
-
 config VGA_BIOS_FILE
 	string
 	default "amipci_01.20"

src/mainboard/intel/d945gclf/Kconfig

@@ -31,8 +31,4 @@ config IRQ_SLOT_COUNT
 	int
 	default 18
 
-config MAX_CPUS
-	int
-	default 4
-
 endif # BOARD_INTEL_D945GCLF

src/mainboard/kontron/986lcd-m/Kconfig

@@ -31,10 +31,6 @@ config IRQ_SLOT_COUNT
 	int
 	default 18
 
-config MAX_CPUS
-	int
-	default 4
-
 config VGA_BIOS_FILE
 	string
 	default "amipci_01.20"

src/mainboard/roda/rk886ex/Kconfig

@@ -32,10 +32,6 @@ config IRQ_SLOT_COUNT
 	int
 	default 18
 
-config MAX_CPUS
-	int
-	default 4
-
 config MAXIMUM_SUPPORTED_FREQUENCY
 	int
 	default 400

src/northbridge/intel/i945/Kconfig

@@ -73,4 +73,8 @@ config SMM_RESERVED_SIZE
 	hex
 	default 0x100000
 
+config MAX_CPUS
+	int
+	default 4
+
 endif