intel_sst: internal speaker needs setting a GPIO line

On Moorestown platform, internal speaker's power line is connected to a GPIO
line, so we need to enable or disable it properly.

Reviewed-by: Wu Fengguang <fengguang.wu@intel.com>
Signed-off-by: Jeff Cheng <jeff_cheng@wistron.com>
Signed-off-by: Lu Guanqun <guanqun.lu@intel.com>
Signed-off-by: Wang Xingchao <xingchao.wang@intel.com>
Signed-off-by: Alan Cox <alan@linux.intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>