After a timeout, reset the controller using SDHCI_RESET_CMD|SDHCI_RESET_DATA
rather than SDHCI_RESET_ALL; the latter turns off clocks and power, removing
any possibility of recovering from the error.

Also, double the timeout to 2 seconds.  Despite what the SD spec says about
all transactions completing in 250ms or less, I have a card which sometimes
takes more than a second to complete a write.