media: uvcvideo: Support multiple frame descriptors with the same dimensions

The Microsoft HoloLens Sensors device has two separate frame descriptors
with the same dimensions, each with a single different frame interval:

      VideoStreaming Interface Descriptor:
        bLength                            30
        bDescriptorType                    36
        bDescriptorSubtype                  5 (FRAME_UNCOMPRESSED)
        bFrameIndex                         1
        bmCapabilities                   0x00
          Still image unsupported
        wWidth                           1280
        wHeight                           481
        dwMinBitRate                147763200
        dwMaxBitRate                147763200
        dwMaxVideoFrameBufferSize      615680
        dwDefaultFrameInterval         333333
        bFrameIntervalType                  1
        dwFrameInterval( 0)            333333
      VideoStreaming Interface Descriptor:
        bLength                            30
        bDescriptorType                    36
        bDescriptorSubtype                  5 (FRAME_UNCOMPRESSED)
        bFrameIndex                         2
        bmCapabilities                   0x00
          Still image unsupported
        wWidth                           1280
        wHeight                           481
        dwMinBitRate                443289600
        dwMaxBitRate                443289600
        dwMaxVideoFrameBufferSize      615680
        dwDefaultFrameInterval         111111
        bFrameIntervalType                  1
        dwFrameInterval( 0)            111111

Skip duplicate dimensions in enum_framesizes, let enum_frameintervals list
the intervals from both frame descriptors. Change set_streamparm to switch
to the correct frame index when changing the interval. This enables 90 fps
capture on a Lenovo Explorer Windows Mixed Reality headset.

[laurent.pinchart@ideasonboard.com: Renamed tmp_ival to ival]

Signed-off-by: Philipp Zabel <philipp.zabel@gmail.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>