DynamicTablesPkg/AmiLib: Fix stack corruption in AmlCodeGenRdInterrupt

In AmlCodeGenRdInterrupt(), the IRQ list was copied directly into an
EFI_ACPI_EXTENDED_INTERRUPT_DESCRIPTOR structure allocated on the stack.
Since the structure only contains storage for the first interrupt entry,
copying multiple IRQs would write beyond the allocated buffer and corrupt
the stack.

Fix this issue by allocating the descriptor dynamically with sufficient
space to accommodate the entire IRQ list. This ensures all interrupt entries
are copied safely without overwriting adjacent stack memory.

Signed-off-by: Tuan Phan <tuan.phan@oss.qualcomm.com>