hw: Fix type constant for DTB files

Commit fcb1ad456c ("system/datadir: Add new type constant for DTB files")
introduced a new type constant for DTB files and converted the boards with
bundled device trees to use it. Convert the other boards for consistency.

Fixes: fcb1ad456c ("system/datadir: Add new type constant for DTB files")
Signed-off-by: Bernhard Beschow <shentey@gmail.com>
Link: https://lore.kernel.org/r/20250610204131.2862-2-shentey@gmail.com
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

hw/arm/boot.c

@@ -527,7 +527,7 @@ int arm_load_dtb(hwaddr addr, const struct arm_boot_info *binfo,
 
     if (binfo->dtb_filename) {
         char *filename;
-        filename = qemu_find_file(QEMU_FILE_TYPE_BIOS, binfo->dtb_filename);
+        filename = qemu_find_file(QEMU_FILE_TYPE_DTB, binfo->dtb_filename);
         if (!filename) {
             fprintf(stderr, "Couldn't open dtb file %s\n", binfo->dtb_filename);
             goto fail;

hw/ppc/e500.c

@@ -408,7 +408,7 @@ static int ppce500_load_device_tree(PPCE500MachineState *pms,
 
     if (dtb_file) {
         char *filename;
-        filename = qemu_find_file(QEMU_FILE_TYPE_BIOS, dtb_file);
+        filename = qemu_find_file(QEMU_FILE_TYPE_DTB, dtb_file);
         if (!filename) {
             goto out;
         }