media: uvcvideo: Use cached memory for USB transfers

Use kmalloc() + DMA streaming API instead of DMA coherent
memory. The coherent memory is uncached and results in slower
decode performance.

Change-Id: Ibb5990adc3bc319fd704534721140644d76a5787
Signed-off-by: Pavankumar Kondeti <quic_pkondeti@quicinc.com>