hal: Use default backend sample rate during device switch

When music and VoIP happen concurrently, and music outputs
with 44.1Khz.  During device switch from speaker to handset,
due to handset and speaker are not same backend, backend
sample rate is set to 44.1Khz, not 48Khz. This causes mute
issue happens.

Fix it by adding backend port comparsion to ensure current
audio device is handset or speaker, and then set sample rate
to 48Khz if backend is same as speaker or handset snd_device.

CRs-Fixed: 2257482
Change-Id: Ia2446d797e6d0b21d536ed40da8deeb29b3132d6
2 files changed