remote-mips.c: Don't install a deprecated_xfer_memory method

remote-mips.c: Don't install a deprecated_xfer_memory method

This removes another yet instance of a deprecated_xfer_memory user.

Tested by building a --enable-targets=all gdb, on x86-64 Fedora 17.

gdb/
2014-02-26  Pedro Alves  <palves@redhat.com>

	* remote-mips.c (mips_xfer_memory): Adjust as to_xfer_partial
	helper.
	(mips_xfer_partial): New function.
	(_initialize_remote_mips): Don't install a deprecated_xfer_memory
	hook.  Install a to_xfer_partial hook.