Fixed UART deinit, some cosmetic changes.
Initial version of SSP and SPI over IRQ classes.
Refactored Serial configuration for LPC13xx.
Refactored LPC17xx Serial configuration.
Refactored UART pins initialization for LPC17xx.
Reordered code, fixed UART pin init for LPC13xx.
Removed unused interrupt support in SerialDma.
Refactored SSP configuration for LPC13xx.
Renamed SpiIrq to Spi.
Refactored SSP class constructor.
Simplified peripheral destructors.
LPC13xx: refactored SPI class.
Reordered SPI class code, removed unused headers.