Remove most gmp-mparam.h headers.

Most gmp-mparam.h headers in glibc define various macros to the same
values they would be defined to by the generic version of that header,
plus macros IEEE_DOUBLE_BIG_ENDIAN or IEEE_DOUBLE_MIXED_ENDIAN related
to the representation of double.  The latter macros are in turn only
used in gmp-impl.h to define union ieee_double_extract, which is not
used in glibc.  Thus all of these headers, except for the generic one
and those that define _LONG_LONG_LIMB for ILP32 configurations with
64-bit registers, are redundant, and this patch removes them.

Tested with build-many-glibcs.py that installed stripped shared
libraries are unchanged by this patch.