ARM: Update Formula to compute MADT size using new callbacks in gic_hw_operations

ARM: Update Formula to compute MADT size using new callbacks in gic_hw_operations

estimate_acpi_efi_size needs to be updated to provide correct size of
hardware domains MADT, which now adds ITS information as well.

This patch updates the formula to compute extra MADT size, as per GICv2/3
by calling gic_get_hwdom_extra_madt_size.

Signed-off-by: Manish Jaggi <mjaggi@cavium.com>
Acked-by: Julien Grall <julien.grall@arm.com>
Reviewed-by: Stefano Stabellini <sstabellini@kernel.org>