habanalabs: Read upper bits of trace buffer from RWPHI

The trace buffer address is 40 bits wide.
The end of the buffer is set in the RWP register (lower 32 bits), and in
the RWPHI register (upper 8 bits).
Currently only the lower 32 bits are read, and this patch fixes it and
concatenates the upper 8 bits to the output address.

Signed-off-by: Tomer Tayar <ttayar@habana.ai>
Reviewed-by: Oded Gabbay <oded.gabbay@gmail.com>
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>