hal: Enable support to dynamically load config files

QCV allows multiple chipsets to be supported on a single
vendor. Enable support to dynamically get configuration
file path in vendor and load audio configuration files.

If 'ro.boot.product.vendor.sku' is not set, audio config
files would be loaded from /vendor/etc/.
If the property is set, files would be loaded from
/vendor/etc/audio/sku_{ro.boot.product.vendor.sku}.

'ro.boot.product.vendor.sku' would be set to SoC/SKU
at boot up in vendor.

Change-Id: Id228d94735b239e7608dfe84dd5f1eec7b016d2b