arm64: defconfig: Add Ceva ahci to the defconfig

The Ceva ahci controller is available on the Xilinx Zynq UltraScale+
MPSoC.

Signed-off-by: Suneel Garapati <suneel.garapati@xilinx.com>
Signed-off-by: Michal Simek <michal.simek@xilinx.com>
[catalin.marinas@arm.com: removed unnecessary defconfig changes]
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>