freq.py: calculate column widths dynamically

Some tracepoints have names longer than the fixed 15 characters which
results in a hard to read table. Let's adjust column width to the
tracepoint name length, with a minimum width of 15, as before.
mmu: add mmu_vma_fault() tracepoint
scripts: hacky fault-contention by vma grouping
gdb: make 'osv mmap' show VMA address
mmu: trace vma path
pagecache: enlarge