[PATCH 02/10] mISDN: Replace GPL notice boilerplate with SPDX identifier

[kernel test robot]

Hi Bagas,

kernel test robot noticed the following build warnings:

[auto build test WARNING on ac9a78681b921877518763ba0e89202254349d1b]

url:    https://github.com/intel-lab-lkp/linux/commits/Bagas-Sanjaya/agp-amd64-Remove-GPL-distribution-notice/20230511-214307
base:   ac9a78681b921877518763ba0e89202254349d1b
patch link:    https://lore.kernel.org/r/20230511133406.78155-3-bagasdotme%40gmail.com
patch subject: [PATCH 02/10] mISDN: Replace GPL notice boilerplate with SPDX identifier
reproduce:
        scripts/spdxcheck.py

If you fix the issue, kindly add following tag where applicable
| Reported-by: kernel test robot <lkp at intel.com>
| Link: https://lore.kernel.org/oe-kbuild-all/202305121151.UPlaFk6c-lkp@intel.com/

spdxcheck warnings: (new ones prefixed by >>)
>> drivers/isdn/mISDN/dsp_audio.c: 1:28 Invalid License ID: GPL-1.0-or-later
>> drivers/isdn/mISDN/dsp_blowfish.c: 1:28 Invalid License ID: GPL-1.0-or-later
>> drivers/isdn/mISDN/dsp_cmx.c: 1:28 Invalid License ID: GPL-1.0-or-later
>> drivers/isdn/mISDN/dsp_core.c: 1:28 Invalid License ID: GPL-1.0-or-later
>> drivers/isdn/mISDN/dsp_dtmf.c: 1:28 Invalid License ID: GPL-1.0-or-later
>> drivers/isdn/mISDN/dsp_tones.c: 1:28 Invalid License ID: GPL-1.0-or-later

-- 
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