gpu: ipu-v3: Add queued image conversion support

This patch implements image conversion support using the IC tasks, with
tiling to support scaling to and from images up to 4096x4096. Image
rotation is also supported. Image conversion requests are added to
a run queue under the IC tasks.

The internal API is subsystem agnostic (no V4L2 dependency except
for the use of V4L2 fourcc pixel formats).

Callers prepare for image conversion by calling
ipu_image_convert_prepare(), which initializes the parameters of
the conversion. The caller passes in the ipu and IC task to use for
the conversion, the input and output image formats, a rotation mode,
and a completion callback and completion context pointer:

struct ipu_image_converter_ctx *
ipu_image_convert_prepare(struct ipu_soc *ipu, enum ipu_ic_task ic_task,
                          struct ipu_image *in, struct ipu_image *out,
                          enum ipu_rotate_mode rot_mode,
                          ipu_image_converter_cb_t complete,
                 ...