pte_t should be the real thing on arm32

[jermar]

On arm32, the type describing the PTE (page table entry) is defined like this:

typedef struct {

unsigned dummy : 32;

} pte_t;

And the real definition is split between pte_level0_t and pte_level1_t types.
It would be more consistent with the rest of the system if the whole thing was declared in pte_t, using a union:

typedef union {

"PTE level 0 stuff"
"PTE level 1 stuff"

} pte_t;

[jermar]

Fixed in changeset:head,151.