Issues with new ARMv8 MPU attributes

[kjbracey]

I just noticed the new MPU_ATTR_NORMAL_OUTER_NON_CACHEABLE etc defines.

A few issues with these, in descending order of importance:

• The TR transient indication is inverted. Bit 3 needs to be set for transient.
• The 0b binary prefix requires a very recent language standard or a compiler extension.
• Shouldn't they have an ARM_ prefix to match surrounding defines?
• But is the OUTER_ and INNER_ necessary?

And as an aside, just for anyone happening to search and end up here - it's not specified anywhere what the "transient" flags of the default memory map are. Apparently the default regions are transient in the M55, which surprised me.

[JonatanAntoni]

Would you mind raising a PR with your proposed changes? Perhaps switch over to ARM-software/CMSIS6 and we leave it unchanged here. Adding `ARM` prefix might be a good idea but would break backward compatibility.