forked from Mirrors/opensbi

Currently, the tlb range flush threshold is fixed and set to 4k for all platforms. However, it should be platform specific as it completely depends upon how platform actually implements sfence instruction. Define a platform feature that allows every individual platform to set different values. If a platform doesn't define it, just use a page size as the threshold. Signed-off-by: Atish Patra <atish.patra@wdc.com> Reviewed-by: Bin Meng <bmeng.cn@gmail.com> Reviewed-by: Anup Patel <anup.patel@wdc.com>