reorganizing at91 subtargets based on sama5 soc features and this fix
below problems.
1. able to set neon flags to sama5d2 & sama5d4 subtargets.
2. fix the make clean which removes all the subtargets in bin folder.
3. able to configure kernel specific to subtarget.
4. able to set vfpu4 flags to samad3 subtargets.
Signed-off-by: Sandeep Sheriker Mallikarjun <sandeepsheriker.mallikarjun@microchip.com>
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>
