Fix old Pentax'es (K10D/K20D) not being recognized (march 2011 regression).
Fix old Pentax'es (K10D/K20D) not being recognized (march 2011 regression).

git-svn-id: 04e88ac4940b0408b73cd6f458a224a262abaaff@609 ec705bc8-faf6-4f9b-9aff-b4916e9bedc3

jbuchbinder/rawspeed,jbuchbinder/rawspeed