crypto: ccp: Make snp_range_list static

Fix:

  drivers/crypto/ccp/sev-dev.c:93:28: sparse: sparse: symbol 'snp_range_list' was not declared. Should it be static?

Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202402031410.GTE3PJ1Y-lkp@intel.com
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/202402031410.GTE3PJ1Y-lkp@intel.com