ARM: davinci_all_defconfig: Enable CPPI 4.1 USB OTG DMA

CPPI 4.1 DMA is now supported on AM18xx.
Update the config to use it instead of PIO mode.

Signed-off-by: Alexandre Bailon <abailon@baylibre.com>
Signed-off-by: Sekhar Nori <nsekhar@ti.com>