Renaming at91 subtarget sama5d3 to sama5 and using at91-sama5d3_xplained
as a target device in sama5 subtarget.This will enable to add other
sama5d2 & sama5d4 target devices in sama5 subtraget.This will avoid
code duplication when sama5d2 & sama5d4 added as different subtarget.
Signed-off-by: Sandeep Sheriker Mallikarjun <sandeepsheriker.mallikarjun@microchip.com>
