drm/panfrost: Remove type name from internal struct again

Commit 72655fb9 ("drm/panfrost: replace endian-specific types with
native ones") accidentally reverted part of the parent commit
7228d9d7 ("drm/panfrost: Remove type name from internal structs")
leading to the situation that the Panfrost UAPI header still doesn't
compile correctly in C++.

Revert the accidental revert and pass me a brown paper bag.
Reported-by: Alyssa Rosenzweig <alyssa@collabora.com>
Fixes: 72655fb9 ("drm/panfrost: replace endian-specific types with native ones")
Signed-off-by: Steven Price <steven.price@arm.com>
Reviewed-by: Alyssa Rosenzweig <alyssa@collabora.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20221103114036.1581854-1-steven.price@arm.com

include/uapi/drm/panfrost_drm.h

@@ -254,7 +254,7 @@ struct panfrost_dump_object_header {
 			__u64 nbos;
 		} reghdr;
 
-		struct pan_bomap_hdr {
+		struct {
 			__u32 valid;
 			__u64 iova;
 			__u32 data[2];