lib: Introduce SBI_TLB_INFO_INIT() helper macro

We introduce SBI_TLB_INFO_INIT() helper macro to help easy
initialization of struct sbi_tlb_info which is passed to the
sbi_tlb_request() API.

Signed-off-by: Anup Patel <anup.patel@wdc.com>
Reviewed-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Atish Patra <atish.patra@wdc.com>