When doing vendor dma transfer wait for SDHC_TRANSFER_COMPLETE.

From jmcneill@ with some layout changes from me.
Small markup fixes:
* Use \e instead of \\ to represent a backslash;
* Dont' start a line with .SUFFIXES.
fix some more registers
__SHIFTOUT -> __SHIFTIN when writing to a reg
Cleanup and __BIT()ify