FRV: Fix linux/elf-fdpic.h

It seems I accidentally switched the guard on linux/elf-fdpic.h from #ifdef
__KERNEL__ to #ifndef __KERNEL__ when attempting to expand the guarded region
to cover the elf_fdpic_params struct when doing the UAPI split - with the
result that the struct became unavailable to kernel code.

Move incorrectly guarded bits back to the kernelspace header.

Whilst we're at it, the __KERNEL__ guards can be deleted as they're no longer
necessary.

Reported-by: Fengguang Wu <fengguang.wu@intel.com>
Reported-by: Lars-Peter Clausen <lars@metafoo.de>
Signed-off-by: David Howells <dhowells@redhat.com>
cc: Fengguang Wu <fengguang.wu@intel.com>
cc: Lars-Peter Clausen <lars@metafoo.de>
cc: uclinux-dev@uclinux.org
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>