hal: Tell Huawei acdb loader which files to load

Huaweis's audio.primary.msm8916 HAL constructs this path from
/sys/bus/platform/drivers/hw_audio_info/hw_audio_info/product_identifier.

Change-Id: I34034d1c7365ebf704be033293821377fb5ce615

hal: Make HUAWEI_SOUND_PARAM_PATH a board flag

There's no reason for HUAWEI_SOUND_PARAM_PATH to be a global cflag.

Change-Id: Ib7d0a401d9bea9388fcc167ec8dc30c897ab54e9

hal: Dynamically load the correct path for HUAWEI_SOUND_PARAM_PATH

Rather than specify a single hard-coded path, use the sysfs interface
that Huawei exports to correctly identify the product-identifier for
the device and dynamically compute the correct path for the sound_param_path.

Change-Id: I8a0f771c2ecca553ea4a550f0fee75fdbfed4a71