Use libm_alias macros in m68k llrint functions.

Use libm_alias macros in m68k llrint functions.

Most m68k libm functions share code via sources for one function
including those for another function or type, in a way that will
require significant changes to create function aliases in a way
friendly to adding _FloatN / _FloatNx aliases.

The llrint function implementations, however, use a conventional
separate implementation for each floating-point type.  Thus preparing
them for _FloatN / _FloatNx aliases is just a matter of changing them
to include the appropriate headers and use the appropriate macros,
which this patch does.  The llrintl changes aren't strictly required,
since m68k long double does not meet the criteria for a _FloatN /
_FloatNx type, but are included anyway to keep consistency between the
implementations for the three types.

Tested with build-many-glibcs.py that installed stripped shared
libraries for m68k-linux-gnu are unchanged by the patch.

	* sysdeps/m68k/m680x0/fpu/s_llrint.c: Include
	<libm-alias-double.h>.
	(llrint): Define using libm_alias_double.
	* sysdeps/m68k/m680x0/fpu/s_llrintf.c: Include
	<libm-alias-float.h>.
	(llrintf): Define using libm_alias_float.
	* sysdeps/m68k/m680x0/fpu/s_llrintl.c: Include
	<libm-alias-ldouble.h>.
	(llrintl): Define using libm_alias_ldouble.