lib: sbi: Set gva when creating sbi_trap_info

In some cases the sbi_trap_info argument passed to sbi_trap_redirect is
created from scratch by filling its fields. Since we previously added a
gva field to struct sbi_trap_info, initialize gva in these cases also.

Suggested-by: Andrew Jones <ajones@ventanamicro.com>
Signed-off-by: Vivian Wang <dramforever@live.com>
Reviewed-by: Andrew Jones <ajones@ventanamicro.com>
Reviewed-by: Anup Patel <anup@brainfault.org>