[PATCH 3/5] drm/panfrost: Add a no execute flag for BO allocations

[Alyssa Rosenzweig]

> User space shouldn't care too much - other than the size of buffers
> allocated being rounded up to the CPU's page size. At least the Panfrost
> user/kernel ABI has sizes in bytes not pages (unlike kbase).

We've been rounding everything up to the nearest 4k in mesa, out of old
habit from kbase. I don't know if that's strictly necessary / helpful
anymore?