arch-arm,arch-sparc: Remove legacy stat for faults

This is a legacy stat that was not easy to tie to a Stats::Group.

In ARM, this stat wasn't actually counting all faults, it was only
counting the faults that occured in 32-bit mode, so it's probably safe
to remove the stat (it was wrong anyway). For SPARC, it's also unlikely
anyone is depending on this stat for their research.

Change-Id: Ic6c60526ea51467627535d732258c50ce0d2c03b
Signed-off-by: Jason Lowe-Power <jason@lowepower.com>
Reviewed-on: https://gem5-review.googlesource.com/c/public/gem5/+/52504
Reviewed-by: Gabe Black <gabe.black@gmail.com>
Reviewed-by: Giacomo Travaglini <giacomo.travaglini@arm.com>
Maintainer: Giacomo Travaglini <giacomo.travaglini@arm.com>
Tested-by: kokoro <noreply+kokoro@google.com>
4 files changed