mpfr : moved unused files to obsolete dir

Signed-off-by: Frans Meulenbroeks <fransmeulenbroeks@gmail.com>

diff --git a/recipes/mpfr/dont_use_mips_h_constraint.patch b/recipes/obsolete/mpfr/dont_use_mips_h_constraint.patch
similarity index 100%
rename from recipes/mpfr/dont_use_mips_h_constraint.patch
rename to recipes/obsolete/mpfr/dont_use_mips_h_constraint.patch