cxl: Set endianess of kernel contexts

A process element (defined in CAIA) keeps track of the endianess of
contexts through the Little Endian (LE) bit of the State Register. It
is currently set for user contexts, but was somehow forgotten for
kernel contexts, so this patch fixes it.
It could lead to erratic behavior from an AFU when the context is
attached through the kernel API.

Fixes: 2f663527 ("cxl: Configure PSL for kernel contexts and merge code")
Cc: stable@vger.kernel.org # 4.2+
Signed-off-by: Frederic Barrat <fbarrat@linux.vnet.ibm.com>
Suggested-by: Michael Neuling <mikey@neuling.org>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>