sparc: Remove ununsed ifunc assembly macros

Now that all SPARC ifunc converted to C implementation there is no need
for both C and assembly macros.  This patch removes the assembly ones.

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

	* sysdeps/sparc/sparc-ifunc.h (SPARC_ASM_IFUNC_DFLT,
	SPARC_ASM_IFUNC1, SPARC_ASM_IFUNC2, SET, SPARC_ASM_VIS2_IFUNC,
	SPARC_ASM_VIS3_IFUNC, SPARC_ASM_VIS3_VIS2_IFUNC): Remove macros.

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