Fix hstatus.GVA and mstatus.GVA updation

The hstatus.GVA and mstatus.GVA should be set only when guest virtual
address is written to stval or mtval CSRs at time of taking trap.

This patch update access, page fault, and guest page fault trap classes
so that we can pass gva flag correct from source of the trap.

Signed-off-by: Anup Patel <anup.patel@wdc.com>