perf maps: Mark ksymbol DSOs with kernel type

We add ksymbol map into machine->kmaps, so it needs to be created as
'struct kmap', which is dependent on its dso having kernel type.

Reported-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Signed-off-by: Jiri Olsa <jolsa@kernel.org>
Tested-by: Ravi Bangoria <ravi.bangoria@linux.ibm.com>
Tested-by: Kim Phillips <kim.phillips@amd.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>
Link: http://lore.kernel.org/lkml/20200210200847.GA36715@krava


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>