sparc: Implement memcpy/mempcpy ifunc selection in C

sparc: Implement memcpy/mempcpy ifunc selection in C

This patch refactor the SPARC64 ifunc selector to a C implementation.
The x86_64 implementation is used as default, which resulted in common
definitions (ifunc-init.h) used on both architectures.  No functional
change is expected, including ifunc resolution rules.

Checked on sparc64-linux-gnu, sparcv9-linux-gnu and x86_64-linux-gnu.

	* sysdeps/sparc/sparc32/sparcv9/multiarch/memcpy-ultra1.S: New
	file.
	* sysdeps/sparc/sparc32/sparcv9/multiarch/memcpy.c: Likewise.
	* sysdeps/sparc/sparc32/sparcv9/multiarch/mempcpy.c: Likewise.
	* sysdeps/sparc/sparc64/multiarch/ifunc-memcpy.h: Likewise.
	* sysdeps/sparc/sparc64/multiarch/memcpy-ultra1.S: Likewise.
	* sysdeps/sparc/sparc64/multiarch/memcpy.c: Likewise.
	* sysdeps/sparc/sparc64/multiarch/mempcpy.c: Likewise.
	* sysdeps/sparc/sparc-ifunc.h (sparc_libc_ifunc_redirected): New
	macro.
	* sysdeps/sparc/sparc32/sparcv9/multiarch/Makefile
	[$(subdir) = string] (sysdep_routines): Add memcpy-ultra1.
	* sysdeps/sparc/sparc64/multiarch/Makefile [$(subdir) = string]
	(sysdep_routines): Add memcpy-ultra1.
	* sysdeps/sparc/sparc64/multiarch/memcpy.S: Remove file.
	* sysdeps/sparc/sparc32/sparcv9/multiarch/memcpy.S: Likewise.

Signed-off-by: Adhemerval Zanella <adhemerval.zanella@linaro.org>