accel/ivpu: Remove support for uncached buffers

Usages of DRM_IVPU_BO_UNCACHED should be replaced by DRM_IVPU_BO_WC.
There is no functional benefit from DRM_IVPU_BO_UNCACHED if these
buffers are never mapped to host VM.

This allows to cut the buffer handling code in the kernel driver
by half.

Usage of DRM_IVPU_BO_UNCACHED buffers was removed from user-space
driver and will not be part of first UMD release.

Signed-off-by: Jacek Lawrynowicz <jacek.lawrynowicz@linux.intel.com>
Reviewed-by: Jeffrey Hugo <quic_jhugo@quicinc.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231031073156.1301669-4-stanislaw.gruszka@linux.intel.com