xtensa: fix libgcc build with --text-section-literals

xtensa: fix libgcc build with --text-section-literals

Functions __muldf3_aux, __divdf3_aux, __mulsf3_aux and __divsf3_aux
don't start with leaf_entry, so they need explicit .literal_position,
otherwise libgcc build fails in the presence of --text-section-literals.

2016-02-17  Max Filippov  <jcmvbkbc@gmail.com>
libgcc/
	* config/xtensa/ieee754-df.S (__muldf3_aux, __divdf3_aux): Add
	.literal_position before the function.
	* config/xtensa/ieee754-sf.S (__mulsf3_aux, __divsf3_aux):
	Likewise.

From-SVN: r233505