imx: spl_imx_romapi: typo fix

Unknow->Unknown

Signed-off-by: Peng Fan <peng.fan@nxp.com>
diff --git a/arch/arm/mach-imx/spl_imx_romapi.c b/arch/arm/mach-imx/spl_imx_romapi.c
index 830d5d1..9164045 100644
--- a/arch/arm/mach-imx/spl_imx_romapi.c
+++ b/arch/arm/mach-imx/spl_imx_romapi.c
@@ -367,7 +367,7 @@
 		printf("USB boot\n");
 		break;
 	default:
-		printf("Unknow (0x%x)\n", bstage);
+		printf("Unknown (0x%x)\n", bstage);
 	}
 
 	if (is_boot_from_stream_device(boot))