Fixed include guard names.
Added bit definitions for SDMMC registers.
Added build option for SDMMC modules.
Added initial version of SDMMC base module.
Card initialization works. Code based on NXP examples.
Started refactoring of SDIO interfaces.
Added build options for SDIO classes.
Added SdCard class, updated SdioSpi.
Updated SdioSpi class.
Fixed command execution. Initialization, CMD0 and CMD8 works fine.
Updated command execution in SdioSpi module.
Updated error codes.
Updated error processing in SdioSpi and SdCard.
Implemented SDIO connection detection.
Added option to detect SDIO connection mode: SPI, SDIO 1-bit or SDIO 4-bit.
Updated existing code to support SPI and native modes.
Fixed reading of long response in SdioSpi.
Added reading of CSD register in SdCard class.
CSD register is used in calculation of the total number of blocks.
Fixed calculation of block count in SdCard.
Common SDIO definitions moved to separate files.
Merge branch 'sdmmc'
Minor fixes.
Refactored base Sdmmc class.
Initial version of asynchronous SdioSpi interface.