Fixes some width in wt_dcache.

Created by: lingscale

width of wtag in wbuffer_t should be PLEN-3, or DCACHE_TAG_WIDTH+DCACHE_INDEX_WIDTH-3.

width of wbuffer_cmp_addr should be PLEN.

width of the second param of is_inside_*_regions should be 64bits.

'cause of the reorgnizaiton of cva6, I can't fix conflicts of last pr #728, so I open a new pr.