SAMA5: Add ADC-side of the logic to hook in timer/counter logic needed to drive  periodic ADC sampling

SAMA5:  Hook RTC into build system; Finish RTC alarm logic; Verify correct behavior of the basic RTC functionality

SAMA5 LCD:  Move framebuffers to center of free memory region.  That creates a guard band around the framebuffers that gives a little protection from any bad writes into the framebuffer

Misc changes to README files; Update SAMA5D3x-EK NxWM configuration to use Calibration instruction messages

SAMA5 LCDC:  Correct how framebuffer memory was being mapped; Remove options to get framebuffer memory in various.  Because of the mapping and aligment requirements, those options really cannot be supported

SAMA5 LCDC:  Wait when the LCDC is resynchronizing (SIF); Try start-up parameters from Barebox (this still don't work)

SAMA5 LCDC: Default resolution if now RGB565; Add option to select a different output resolution than the sofware resolution (needs to the 24BPP for this LCD).

SAMA5 LCDC: Move DMA descriptors out of internal SRAM and into SDRAM. I am not completely clear, but it looks like the LCDC cannot support DMA from internal SRAM