feat(plat/qemu): add sdei support for QEMU

Add sdei support for QEMU, this is to let jailhouse Hypervisor
use SDEI to do hypervisor management, after physical IRQ
has been disabled routing.

Note: To enable SDEI in QEMU, it needs to set "SDEI_SUPPORT=1
EL3_EXCEPTION_HANDLING=1" when compiling.

Signed-off-by: Dongjiu Geng <gengdongjiu1@gmail.com>
Change-Id: Ia7f9c5a0db36da03e5c6e6fb1270281f19924d77
3 files changed