arm64: Set SD_ASYM_CPUCAPACITY topology flag for asymmetric cpu capacity systems

In addition to adjusting the cpu capacities asymmetric cpu capacity
systems also have to set the SD_ASYM_CPUCAPACITY topology flag to inform
the scheduler to look harder when load balancing. This patch sets the
topology flag on DIE level for such systems based on the cpu capacities
provided through DT or sysfs.

cc: Catalin Marinas <catalin.marinas@arm.com>
cc: Will Deacon <will.deacon@arm.com>

Signed-off-by: Morten Rasmussen <morten.rasmussen@arm.com>