Support level triggered interrupts with VT-x virtual interrupt delivery.

The VMCS field EOI_bitmap[] is an array of 256 bits - one for each vector.
If a bit is set to '1' in the EOI_bitmap[] then the processor will trigger
an EOI-induced VM-exit when it is doing EOI virtualization.

The EOI-induced VM-exit results in the EOI being forwarded to the vioapic
so that level triggered interrupts can be properly handled.

Tested by:	Anish Gupta (akgupt3@gmail.com)