x86: Enable multi-core init for Minnowboard MAX

Enable the CPU uclass and Simple Firmware interface for Minnowbaord MAX. This
enables multi-core support in Linux.

Signed-off-by: Simon Glass <sjg@chromium.org>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>

arch/x86/dts/minnowmax.dts

@@ -68,6 +68,26 @@
 		stdout-path = "/serial";
 	};
 
+	cpus {
+		#address-cells = <1>;
+		#size-cells = <0>;
+
+		cpu@0 {
+			device_type = "cpu";
+			compatible = "intel,baytrail-cpu";
+			reg = <0>;
+			intel,apic-id = <0>;
+		};
+
+		cpu@1 {
+			device_type = "cpu";
+			compatible = "intel,baytrail-cpu";
+			reg = <1>;
+			intel,apic-id = <4>;
+		};
+
+	};
+
 	spi {
 		#address-cells = <1>;
 		#size-cells = <0>;

configs/minnowmax_defconfig

@@ -8,3 +8,7 @@ CONFIG_FRAMEBUFFER_SET_VESA_MODE=y
 CONFIG_FRAMEBUFFER_VESA_MODE_11A=y
 CONFIG_MMCONF_BASE_ADDRESS=0xe0000000
 CONFIG_HAVE_INTEL_ME=y
+CONFIG_GENERATE_SFI_TABLE=y
+CONFIG_CPU=y
+CONFIG_CMD_CPU=y
+CONFIG_SMP=y