clover: implement clSetKernelArgSVMPointer

clover: implement clSetKernelArgSVMPointer

it is pretty much identical to a clSetKernelArg for a scalar field, except
it is only valid for global and constant memory pointers.

Also the type equals void* on the Host, so we can just check the size of it.

v2: prefer using target_size to extend the pointer value
v3: handle more corner cases in combiation to clSetKernelArg

Signed-off-by: Karol Herbst <kherbst@redhat.com>
Reviewed-by: Pierre Moreau <dev@pmoreau.org>
Reviewed-by: Francisco Jerez <currojerez@riseup.net>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/2076>