x86/mcheck: address violations of MISRA C:2012 Rule 7.2

x86/mcheck: address violations of MISRA C:2012 Rule 7.2

The xen sources contains violations of MISRA C:2012 Rule 7.2 whose
headline states:
"A 'u' or 'U' suffix shall be applied to all integer constants
that are represented in an unsigned type".

Add the 'U' suffix to integers literals with unsigned type.

For the sake of uniformity, the following change is made:
- add the 'U' suffix to all first macro's arguments

Signed-off-by: Simone Ballarin <simone.ballarin@bugseng.com>
Signed-off-by: Gianluca Luparini <gianluca.luparini@bugseng.com>
Acked-by: Jan Beulich <jbeulich@suse.com>