hw/timer/hpet: Include "exec/address-spaces.h"

hw/timer/hpet: Include "exec/address-spaces.h"

hw/timer/hpet.c calls address_space_stl_le() declared in
"exec/address-spaces.h". Include it.

This fixes (when modifying unrelated headers):

  hw/timer/hpet.c:210:31: error: use of undeclared identifier 'address_space_memory'
          address_space_stl_le(&address_space_memory, timer->fsb >> 32,
                               ^~~~~~~~~~~~~~~~~~~~

Acked-by: John Snow <[email protected]>
Signed-off-by: Philippe Mathieu-Daudé <[email protected]>
Reviewed-by: Richard Henderson <[email protected]>
Message-Id: <20200228114649[email protected]>
Signed-off-by: Laurent Vivier <[email protected]>