SAMA5D3x-EK: Change name of all board-specific configuration variables so that there are no collisions with names of similar variables for other boards

SAM4E-EK:  Remove bogus LCD driver; replace with information that might be useful to someone who wants to develop an LCD driver for the SAM4E-EK

For all configurations that have the default pthread stacksize set to some other value than 2048 AND which have the USB MSC device class enabled, add a definition of CONFIG_USBMSC_SCSI_STACKSIZE so that the size of the stack used by USB MSC SCSI worker thread does not increase

apps/system/usbmsc:  Back out kludge that is no longer needed with the recent fix to the USB MSC class

Add missing HSCMI configuration options; Make HSMCI configuration naming more compatible; Fix HSCMI clocking to use the CLKODD bit