hw/timer/pxa2xx_timer: replace hw_error() -> qemu_log_mask()

Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: Alistair Francis <alistair.francis@xilinx.com>
Message-id: 20180103224208.30291-2-f4bug@amsat.org
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>