hal: replace with a proper usb detection method

If USB is not the first sink, audioflinger stream setParam won't pass
usb card info as a part of routing parameter. Hence, the usb check
method which relies on card info is useless. Replace with
usb_connected() that enumerates all usb card.

CRs-Fixed: 2648183
Change-Id: Ic3f2ebeb0f9db11a7fe4d7c2bd4136f6db0497aa
1 file changed