drivers: mmc: sdhci-brcmstb: improve bcm2712 card removal handling

If the controller is being reset, then the CQE needs to be reset as well.

For removable cards, CQHCI_SSC1 must specify a polling mode (CBC=0)
otherwise it's possible that the controller stops emitting periodic
CMD13s on card removal, without raising an error status interrupt.

Signed-off-by: Jonathan Bell <jonathan@raspberrypi.com>