i386: Check PIC to enable PIC setups in multiarch functions

Check PIC, instead of SHARED, to enable PIC setups.

	* sysdeps/i386/i686/multiarch/memcmp-sse4.S: Check PIC instead
	of SHARED.
	* sysdeps/i386/i686/multiarch/memcpy-sse2-unaligned.S: Likewise.
	* sysdeps/i386/i686/multiarch/memcpy-ssse3-rep.S: Likewise.
	* sysdeps/i386/i686/multiarch/memcpy-ssse3.S: Likewise.
	* sysdeps/i386/i686/multiarch/memset-sse2-rep.S: Likewise.
	* sysdeps/i386/i686/multiarch/memset-sse2.S: Likewise.
	* sysdeps/i386/i686/multiarch/strcat-sse2.S: Likewise.
	* sysdeps/i386/i686/multiarch/strcpy-sse2.S: Likewise.