Documentation: arch-support: remove obsolete architectures

A number of architecture ports are obsolete and getting dropped,
so we no longer want to track the respective features.

We already removed the lines for metag and mn10300, this does
the same edits for all the others.

For the remaining 21 architectures, this shows how many are known
to implement each given feature:

19 time/modern-timekeeping/arch-support.txt
19 time/clockevents/arch-support.txt
15 core/tracehook/arch-support.txt
14 core/generic-idle-thread/arch-support.txt
13 locking/lockdep/arch-support.txt
12 io/dma-api-debug/arch-support.txt
11 debug/kgdb/arch-support.txt
10 time/virt-cpuacct/arch-support.txt
 9 debug/kretprobes/arch-support.txt
 9 debug/kprobes/arch-support.txt
 8 vm/THP/arch-support.txt
 8 vm/pte_special/arch-support.txt
 8 vm/numa-memblock/arch-support.txt
 8 io/sg-chain/arch-support.txt
 7 perf/kprobes-event/arch-support.txt
 7 locking/rwsem-optimized/arch-support.txt
 7 debug/gcov-profile-all/arch-support.txt
 7 core/jump-labels/arch-support.txt
 7 core/BPF-JIT/arch-support.txt
 6 vm/ELF-ASLR/arch-support.txt
 6 time/context-tracking/arch-support.txt
 6 seccomp/seccomp-filter/arch-support.txt
 6 debug/stackprotector/arch-support.txt
 5 time/irq-time-acct/arch-support.txt
 5 io/dma-contiguous/arch-support.txt
 5 debug/uprobes/arch-support.txt
 4 vm/ioremap_prot/arch-support.txt
 4 time/arch-tick-broadcast/arch-support.txt
 4 perf/perf-stackdump/arch-support.txt
 4 perf/perf-regs/arch-support.txt
 3 debug/KASAN/arch-support.txt
 2 vm/PG_uncached/arch-support.txt
 2 vm/huge-vmap/arch-support.txt
 2 sched/numa-balancing/arch-support.txt
 2 sched/membarrier-sync-core/arch-support.txt
 2 locking/cmpxchg-local/arch-support.txt
 2 debug/optprobes/arch-support.txt
 2 debug/kprobes-on-ftrace/arch-support.txt
 1 vm/TLB/arch-support.txt
 1 locking/queued-spinlocks/arch-support.txt
 1 locking/queued-rwlocks/arch-support.txt
 1 debug/user-ret-profiler/arch-support.txt
 0 lib/strncasecmp/arch-support.txt

Note that the list does not include riscv or nds32 yet, these still
need to be added.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>