arm64: Fix the endianness of arch_spinlock_t

The owner and next members of the arch_spinlock_t structure need to be
swapped when compiling for big endian.

Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Reported-by: Matthew Leach <matthew.leach@arm.com>
Acked-by: Will Deacon <will.deacon@arm.com>
Git-commit: 4a12cae7ef2612eb094c4b48e8b37cf837e3df55
Git-repo: git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git


Signed-off-by: Ian Maund <imaund@codeaurora.org>