The current rXXXX event specification creates event under PERF_TYPE_RAW
pmu type. This change allows to use rXXXX within pmu syntax, so it's
type is used via the following syntax:

  -e 'cpu/r3c/'
  -e 'cpum_cf/r0/'

The XXXX number goes directly to perf_event_attr::config the same way as
in '-e rXXXX' event. The perf_event_attr::type is filled with pmu type.

Committer testing:

So, lets see what goes in perf_event_attr::config for, say, the
'instructions' PERF_TYPE_HARDWARE (0) event, first we should look at how
to encode this event as a PERF_TYPE_RAW event for this specific CPU, an
AMD Ryzen 5:

  # cat /sys/devices/cpu/events/instructions
  event=0xc0
  #

Then try with it _and_ the instruction, just to see that they are close
enough:

  # perf stat -e rc0,instructions sleep 1

   Performance counter stats for 'sleep 1':

             919,794      rc0
             919,898      instructions

         1.000754579 seconds time elapsed

         0.000715000 seconds user
         0.000000000 seconds sys
  #

Now we should try, before this patch, the PMU event encoding:

  # perf stat -e cpu/rc0/ sleep 1
  event syntax error: 'cpu/rc0/'
                           \___ unknown term

  valid terms: event,edge,inv,umask,cmask,config,config1,config2,name,period,percore
  #

Now with this patch, the three ways of specifying the 'instructions' CPU
counter are accepted:

  # perf stat -e cpu/rc0/,rc0,instructions sleep 1

   Performance counter stats for 'sleep 1':

             892,948      cpu/rc0/
             893,052      rc0
             893,156      instructions

         1.000931819 seconds time elapsed

         0.000916000 seconds user
         0.000000000 seconds sys

  #
Requested-by: Thomas Richter <tmricht@linux.ibm.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Arnaldo Carvalho de Melo <acme@redhat.com>
Tested-by: Thomas Richter <tmricht@linux.ibm.com>
Cc: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Cc: Michael Petlan <mpetlan@redhat.com>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Sumanth Korikkar <sumanthk@linux.ibm.com>
Cc: Vasily Gorbik <gor@linux.ibm.com>
Link: http://lore.kernel.org/lkml/20200416221405.437788-1-jolsa@kernel.orgSigned-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>