linux-phytec-ti

powerpc: Pull out ksp_vsid logic into a helper

The previous patch left a bit of a wart in copy_process(). Clean it up a
bit by moving the logic out into a helper.

Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Benjamin Herrenschmidt <benh@kernel.crashing.org>