MIPS: Remove __init from add_wired_entry()

For Alchemy-PCI I need to add a wired entry after resuming from RAM;
remove the __init from add_wired_entry() so that this actually works.

Signed-off-by: Manuel Lauss <manuel.lauss@googlemail.com>
To: Linux-MIPS <linux-mips@linux-mips.org>
Patchwork: https://patchwork.linux-mips.org/patch/2684/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>