arm: imx8ulp: support print cpu info

Support print cpu info. the clock function has not been added, it will
be added in following patches.
Signed-off-by: NPeng Fan <peng.fan@nxp.com>

arch/arm/include/asm/arch-imx8ulp/sys_proto.h

@@ -8,4 +8,7 @@
 
 #include <asm/mach-imx/sys_proto.h>
 
+extern unsigned long rom_pointer[];
+
+enum bt_mode get_boot_mode(void);
 #endif

arch/arm/mach-imx/imx8ulp/soc.c

@@ -3,9 +3,67 @@
  * Copyright 2021 NXP
  */
 
+#include <asm/io.h>
+#include <asm/arch/clock.h>
+#include <asm/arch/imx-regs.h>
 #include <asm/arch/sys_proto.h>
+#include <asm/mach-imx/boot_mode.h>
 
 u32 get_cpu_rev(void)
 {
 	return (MXC_CPU_IMX8ULP << 12) | CHIP_REV_1_0;
 }
+
+enum bt_mode get_boot_mode(void)
+{
+	u32 bt0_cfg = 0;
+
+	bt0_cfg = readl(CMC0_RBASE + 0x80);
+	bt0_cfg &= (BT0CFG_LPBOOT_MASK | BT0CFG_DUALBOOT_MASK);
+
+	if (!(bt0_cfg & BT0CFG_LPBOOT_MASK)) {
+		/* No low power boot */
+		if (bt0_cfg & BT0CFG_DUALBOOT_MASK)
+			return DUAL_BOOT;
+		else
+			return SINGLE_BOOT;
+	}
+
+	return LOW_POWER_BOOT;
+}
+
+#if defined(CONFIG_DISPLAY_CPUINFO)
+const char *get_imx_type(u32 imxtype)
+{
+	return "8ULP";
+}
+
+int print_cpuinfo(void)
+{
+	u32 cpurev;
+	char cause[18];
+
+	cpurev = get_cpu_rev();
+
+	printf("CPU:   Freescale i.MX%s rev%d.%d at %d MHz\n",
+	       get_imx_type((cpurev & 0xFF000) >> 12),
+	       (cpurev & 0x000F0) >> 4, (cpurev & 0x0000F) >> 0,
+	       mxc_get_clock(MXC_ARM_CLK) / 1000000);
+
+	printf("Boot mode: ");
+	switch (get_boot_mode()) {
+	case LOW_POWER_BOOT:
+		printf("Low power boot\n");
+		break;
+	case DUAL_BOOT:
+		printf("Dual boot\n");
+		break;
+	case SINGLE_BOOT:
+	default:
+		printf("Single boot\n");
+		break;
+	}
+
+	return 0;
+}
+#endif