usb: musb: set TXMAXP and AUTOSET for full speed bulk in device mode

The TXMAXP register is not set correctly for full speed bulk case
when the can_bulk_split() is used. Without this PIO transfers will
not take place correctly

The "mult" factor needs to be updated correctly for the
can_bulk_split() case

The AUTOSET bit in the TXCSR is not being set if the "mult"
factor is greater than 0 for the High Bandwidth ISO case.
But the "mult" factor is also greater than 0 in case of Full speed
bulk transfers with the packet splitting in TXMAXP register

Without the AUTOSET the DMA transfers will not progress in mode1

[ balbi@ti.com : add braces to both branches ]

Change-Id: Ic8dad2dfdcbb2887da32a29994da35472c4cce5a
Signed-off-by: supriya karanth <supriya.karanth@stericsson.com>
Signed-off-by: Praveena NADAHALLY <praveen.nadahally@stericsson.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Felipe Balbi <balbi@ti.com>