microblaze: Fix access_ok macro

There is the problem with bit OR (|) because for
some combination is addr | size | addr+size equal
to seq.

For standard kernel setting (kernel starts at 0xC0000000)
is seq for user space 0xBFFFFFFF and everything below
this limit is fine.

But even address 0xBFFFFFFF is fine because it
is below kernel space.

Signed-off-by: Andrew Fedonczuk <andrew.fedonczuk@ericsson.com>
Signed-off-by: Michal Simek <monstr@monstr.eu>