Update powerpc-nofpu localplt.data for fegetround hidden_proto / hidden_def.

My recent changes that added libm_hidden_proto / libm_hidden_def for
fegetround had the side effect of removing the need for a
localplt.data entry for fegetround for powerpc-nofpu.  This patch
removes that entry.  Tested powerpc-nofpu.

	* sysdeps/unix/sysv/linux/powerpc/powerpc32/nofpu/nptl/localplt.data:
	Don't expect fegetround reference in libm.so.