qemu: replace deprecated plat_psci_common.c
qemu: replace deprecated plat_psci_common.c

Change to compile with new plat/common/plat_psci_common.c instead of the old
deprecated plat/common/aarch64/plat_psci_common.c

Signed-off-by: Jens Wiklander <7706914404370d7502c27a0eff493dcf491feb51@linaro.org>

achingupta/arm-trusted-firmware,lsigithub/arm-trusted-firmware_public,achingupta/arm-trusted-firmware,lsigithub/arm-trusted-firmware_public