USB: m66592-udc: reduce size of data structure.

Poking around with pahole, we see that m66592 handily shoves a u16 in
between larger types on 2 separate occasions leaving us with 2 2-byte
holes:

struct m66592 {
	...

	/* size: 1196, cachelines: 38 */
	/* sum members: 1192, holes: 2, sum holes: 4 */
	/* last cacheline: 12 bytes */
};	/* definitions: 1 */

Pairing them gets back 4-bytes:

struct m66592 {
	...

	/* size: 1192, cachelines: 38 */
	/* last cacheline: 8 bytes */
};	/* definitions: 1 */

Unfortunately it's not enough to save a cacheline with this massive
structure, but every byte helps.

Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Signed-off-by: Yoshihiro Shimoda <shimoda.yoshihiro@renesas.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>