ArmVirtPkg: Install Acpi tables for Cloud Hypervisor

ArmVirtPkg: Install Acpi tables for Cloud Hypervisor

There is no device like Fw-cfg in Qemu in Cloud Hypervisor, so a specific
Acpi handler is introduced here.

The handler implemented here is in a very simple way:
1. acquire the RSDP from the PCD variable in the top ".dsc";
2. get the XSDT address from RSDP structure;
3. get the ACPI tables following the XSDT structure and install them
one by one;
4. get DSDT address from FADT and install DSDT table.

Cc: Laszlo Ersek <lersek@redhat.com>
Cc: Sami Mujawar <sami.mujawar@arm.com>
Signed-off-by: Jianyong Wu <jianyong.wu@arm.com>
Reviewed-by: Sami Mujawar <sami.mujawar@arm.com>