drm/vc4: Use newer fence API properly to fix build errors

The commit 73511edf ("dma-buf: specify usage while adding fences to
dma_resv obj v7") ported all the DRM drivers to use the newer fence API
that specifies the usage with the enum dma_resv_usage rather than doing
an explicit shared / exclusive distinction.

But the commit didn't do it properly in two callers of the vc4 driver,
leading to build errors.

Fixes: 73511edf ("dma-buf: specify usage while adding fences to dma_resv obj v7")
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Christian König <christian.koenig@amd.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20220407131950.915091-1-javierm@redhat.com