parisc: make "make install" not depend on vmlinux

Install targets (install, zinstall, uinstall) on parisc have a
dependency to vmlinux. This may cause parts of the kernel to be rebuilt
during installation. We must avoid this since this may run as root.
Install targets "ABSOLUTELY MUST NOT MODIFY THE SOURCE TREE." as Linus
emphasized this in:

http://lkml.org/lkml/2013/7/10/600

So on parisc and maybe other archs we need the same as for x86:

1648e4f8 x86, kbuild: make "make install" not depend on vmlinux

This parisc patch was inspired by:

19514fc6

 arm, kbuild: make "make install" not depend on vmlinux

Signed-off-by: Helge Deller <deller@gmx.de>