Orion: general cleanup

Various Orion cleanups:
- Unify GPL license banner format across all files.
- Unify naming of .h double inclusion guard preprocessor macros.
- Unify spelling of "PCIe" (variants seen: PCIE, PCIe, PCI-EX.)
- Various typo fixes.
- Remove __init attributes from prototypes declared in headers.
- Remove trailing comments from #endif statements.
- Mark a couple of locally-used-only structs static.

Signed-off-by: Lennert Buytenhek <buytenh@marvell.com>
Reviewed-by: Tzachi Perelstein <tzachi@marvell.com>
Acked-by: Russell King <rmk+kernel@arm.linux.org.uk>
Signed-off-by: Nicolas Pitre <nico@marvell.com>