[media] media: davinci_vpfe: clear the output_specs

clear of the output_specs before passing it to the
configure_resizer_out_params(), so that no garbage values
are set.

This fixes following build warning:
drivers/staging/media/davinci_vpfe/dm365_resizer.c: In function 'resizer_set_stream':
drivers/staging/media/davinci_vpfe/dm365_resizer.c:190:46: warning: 'output_specs.vst_c'
may be used uninitialized in this function [-Wmaybe-uninitialized]
  param->ext_mem_param[index].rsz_sdr_ptr_s_c = output->vst_c;
                                              ^
drivers/staging/media/davinci_vpfe/dm365_resizer.c:316:30: note: 'output_specs.vst_c' was declared here
  struct vpfe_rsz_output_spec output_specs;
                              ^

Signed-off-by: Lad, Prabhakar <prabhakar.csengg@gmail.com>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>