mkimage: add a flag to describe whether -A is specified

The sunxi_egon type used to take no -A argument (because we assume sunxi
targets are all ARM). However, as Allwinner D1 appears as the first
RISC-V sunxi target, we need to support -A; in addition, as external
projects rely on U-Boot mkimage to generate sunxi eGON.BT0 header, we
need to keep compatibility with command line without -A.

As the default value of arch in mkimage is not proper (IH_ARCH_PPC
instead of IH_ARCH_INVALID), to keep more compatibility, add an Aflag
field to image parameters to describe whether an architecture is
explicitly specified.

Reviewed-by: Tom Rini <trini@konsulko.com>
Signed-off-by: Icenowy Zheng <icenowy@aosc.io>
Signed-off-by: Samuel Holland <samuel@sholland.org>
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
diff --git a/tools/imagetool.h b/tools/imagetool.h
index 5169b02..05dd94d 100644
--- a/tools/imagetool.h
+++ b/tools/imagetool.h
@@ -53,6 +53,7 @@
 	int pflag;
 	int vflag;
 	int xflag;
+	int Aflag;
 	int skipcpy;
 	int os;
 	int arch;
diff --git a/tools/mkimage.c b/tools/mkimage.c
index 74bd072..b46216f 100644
--- a/tools/mkimage.c
+++ b/tools/mkimage.c
@@ -172,6 +172,7 @@
 				show_valid_options(IH_ARCH);
 				usage("Invalid architecture");
 			}
+			params.Aflag = 1;
 			break;
 		case 'b':
 			if (add_content(IH_TYPE_FLATDT, optarg)) {