apalis/colibri_t20/t30: integrate recovery mode detection

Allow detecting whether or not U-Boot was launched through the
recovery mode of the resp. NVIDIA SoC.

Make use of a board specific arch_misc_init() and enable the same via
CONFIG_ARCH_MISC_INIT configuration option.

Signed-off-by: Marcel Ziswiler <marcel.ziswiler@toradex.com>
Acked-by: Stephen Warren <swarren@nvidia.com>
Signed-off-by: Tom Warren <twarren@nvidia.com>
diff --git a/board/toradex/colibri_t20/colibri_t20.c b/board/toradex/colibri_t20/colibri_t20.c
index 8ae9ccf..7210a8a 100644
--- a/board/toradex/colibri_t20/colibri_t20.c
+++ b/board/toradex/colibri_t20/colibri_t20.c
@@ -8,8 +8,20 @@
 #include <asm/arch/clock.h>
 #include <asm/arch/funcmux.h>
 #include <asm/arch/pinmux.h>
+#include <asm/arch-tegra/ap.h>
 #include <asm/arch-tegra/board.h>
+#include <asm/arch-tegra/tegra.h>
 #include <asm/gpio.h>
+#include <asm/io.h>
+
+int arch_misc_init(void)
+{
+	if (readl(NV_PA_BASE_SRAM + NVBOOTINFOTABLE_BOOTTYPE) ==
+	    NVBOOTTYPE_RECOVERY)
+		printf("USB recovery mode\n");
+
+	return 0;
+}
 
 #ifdef CONFIG_TEGRA_MMC
 /*