Add configs/sam4l-xplained/src/up_userleds.c
SAM4L GPIO port addressing fixes; SAM4L Xplained LED support; minor documentation updates
Add SAM4L FLASHCALW header file
Add power management register defintions and clock control logic for the SAM4L
Updates to SAM4L clocking. Still not finished
Move SAM4L peripheral clock logic to a separate file
Merge branch 'master' of http://git.code.sf.net/p/nuttx/git into integration_dma
WIP testing with DMA enabled