hexdump: Support any rowsize

At present print_hex_dump() only supports either 16- or 32-byte lines.
With U-Boot we want to support any line length up to a maximum of 64.
Update the function to support this, with 0 defaulting to 16, as with
print_buffer().

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/include/hexdump.h b/include/hexdump.h
index 62fce7a..b75e260 100644
--- a/include/hexdump.h
+++ b/include/hexdump.h
@@ -85,7 +85,7 @@
  * hex_dump_to_buffer - convert a blob of data to "hex ASCII" in memory
  * @buf: data blob to dump
  * @len: number of bytes in the @buf
- * @rowsize: number of bytes to print per line; must be 16 or 32
+ * @rowsize: number of bytes to print per line; max 64
  * @groupsize: number of bytes to print at a time (1, 2, 4, 8; default = 1)
  * @linebuf: where to put the converted data
  * @linebuflen: total size of @linebuf, including space for terminating NUL
@@ -120,7 +120,7 @@
  *  caller supplies trailing spaces for alignment if desired
  * @prefix_type: controls whether prefix of an offset, address, or none
  *  is printed (see enum dump_prefix_t)
- * @rowsize: number of bytes to print per line; must be 16 or 32
+ * @rowsize: number of bytes to print per line; max 64
  * @groupsize: number of bytes to print at a time (1, 2, 4, 8; default = 1)
  * @buf: data blob to dump
  * @len: number of bytes in the @buf