Reserve control code for FIPS extensions.
* src/gcrypt.h.in (GCRYCTL_INACTIVATE_FIPS_FLAG): New. (GCRYCTL_REACTIVATE_FIPS_FLAG): New. * src/global.c (_gcry_vcontrol): Add them but return not_implemented. (cherry picked from commit aea96a64fbc58a0b6f9f435e97e93294c6eb1052)