powerpc: Refactor powerpc32 lrint/lrintf/llrint/llrintf

This patches consolidates all the powerpc llrint{f} implementations on
the generic sysdeps/powerpc/powerpc32/fpu/s_llrint{f}.

Checked on powerpc-linux-gnu (built without --with-cpu, with
--with-cpu=power4 and with --with-cpu=power5+ and --disable-multi-arch),
powerpc64-linux-gnu (built without --with-cpu and with --with-cpu=power5+
and --disable-multi-arch).

	* sysdeps/powerpc/fpu/s_lrintf.S: Remove file.
	* sysdeps/powerpc/powerpc64/fpu/s_lrintf.c: Move to ...
	* sysdeps/powerpc/fpu/s_lrintf.c: ... here.
	* sysdeps/powerpc/powerpc32/fpu/Makefile
	[$(subdir) == math] (CFLAGS-s_lrint.c): New rule.
	* sysdeps/powerpc/powerpc32/fpu/s_llrint.c (__llrint): Add power4
	optimization.
	* sysdeps/powerpc/powerpc32/fpu/s_llrintf.c (__llrintf): Likewise.
	* sysdeps/powerpc/powerpc32/fpu/s_lrint.S: Remove file.
	* sysdeps/powerpc/powerpc32/fpu/s_lrint.c: New file.
	* sysdeps/powerpc/powerpc32/power4/fpu/multiarch/Makefile
	(CFLAGS-s_llrintf-power6.c, CFLAGS-s_llrintf-ppc32.c,
	CFLAGS-s_llrint-power6.c, CFLAGS-s_llrint-ppc32.c,
	CFLAGS-s_lrint-ppc32.c): New rule.
	* sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_llrint-power6.S:
	Remove file.
	* sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_llrint-ppc32.S:
	Likewise.
	* sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_llrintf-power6.S:
	Likewise.
	* sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_llrintf-ppc32.S:
	Likewise.
	* sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_lrint-ppc32.S:
	Likewise.
	* sysdeps/powerpc/powerpc32/power4/fpu/s_llrint.S: Likewise.
	* sysdeps/powerpc/powerpc32/power4/fpu/s_llrintf.S: Likewise.
	* sysdeps/powerpc/powerpc32/power6/fpu/s_llrint.S: Likewise.
	* sysdeps/powerpc/powerpc32/power6/fpu/s_llrintf.S: Likewise.
	* sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_llrint-power6.c:
	New file.
	* sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_llrint-ppc32.c:
	Likewise.
	* sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_llrintf-power6.c:
	Likewise.
	* sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_llrintf-ppc32.c:
	Likewise.
	* sysdeps/powerpc/powerpc32/power4/fpu/multiarch/s_lrint-ppc32.c:
	Likewise.

Reviewed-by: Gabriel F. T. Gomes <gabrielftg@linux.ibm.com>