spl: Remove filename from spl_load_info

For filesystems, filename serves the same purpose as priv. However,
spl_load_fit_image also uses it to determine whether to use a DMA-aligned
buffer. This is beneficial for FAT, which uses a bounce-buffer if the
destination is not DMA-aligned. However, this is unnecessary now that
filesystems set bl_len to ARCH_DMA_MINALIGN instead. With this done, we can
remove filename entirely.

Signed-off-by: Sean Anderson <seanga2@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>

include/spl.h

@@ -287,12 +287,10 @@ static inline void *spl_image_fdt_addr(struct spl_image_info *info)
  *
  * @priv: Private data for the device
  * @bl_len: Block length for reading in bytes
- * @filename: Name of the fit image file.
  * @read: Function to call to read from the device
  */
 struct spl_load_info {
 	void *priv;
-	const char *filename;
 	/**
 	 * read() - Read from device
 	 *