[bt][mediatek] Fix SDIO transfer failures after reboot

SDIO transfers were failing after reboot, causing Bluetooth to not work.
Not setting card ownership on every interrupt fixes this.

Bug: ZX-2787
Test: Rebooted several times, saw no SDIO failures.
Test: Used bt-cli to scan.
Change-Id: I67cf958007fc49364d3f29e0bccb0012dc994a83