Merged MMCSD single read fix from Greg, without change log
Add CAN configuration to STM32 config menu
STM32 BxCAN filter registers are only accessible via the CAN1 register block; teach the code how to get at them.
cdcacm: fixed SELFPOWERED and REMOTEWAKEUP bits in USB attributes

the ifndef checks should be ifdef. This was causing the wrong
attributes on USB, which could limit available power on some host
systems