apollolake: Limit MAX_CPUS to 4

APL does not support Hyper-Threading, and has at most four CPU cores.

Change-Id: Ib2ffadc0c31cdd96bec8eed5364c984acb2e1250
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/45143
Reviewed-by: Mario Scheithauer <mario.scheithauer@siemens.com>
Reviewed-by: Nico Huber <nico.h@gmx.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/mainboard/google/reef/Kconfig

@@ -83,7 +83,7 @@ config MAINBOARD_FAMILY
 
 config MAX_CPUS
 	int
-	default 8
+	default 4
 
 config UART_FOR_CONSOLE
 	int

src/mainboard/siemens/mc_apl1/Kconfig

@@ -42,6 +42,6 @@ config UART_FOR_CONSOLE
 
 config MAX_CPUS
 	int
-	default 8
+	default 4
 
 endif # BOARD_SIEMENS_BASEBOARD_MC_APL1