Added DAC for LPC43xx.
Added definitions for SCT registers.
Added SCT module structure.
Minor updates in descriptions.
Updated Dac class structure.
Added output pin field.
Added spinlocks to crucial modules.
Added spinlocks to GpDma and Pin handlers.
Fixed coding style.
Updated SCT definitions.
Added base SCT class for LPC43xx.
Added simple timer based on SCT peripheral.