pmem, x86: clean up conditional pmem includes
pmem, x86: clean up conditional pmem includes

Prior to this change x86_64 used the pmem defines in
arch/x86/include/asm/pmem.h, and UM used the default ones at the
top of include/linux/pmem.h.  The inclusion or exclusion in linux/pmem.h
was controlled by CONFIG_ARCH_HAS_PMEM_API, but the ones in asm/pmem.h
were controlled by ARCH_HAS_NOCACHE_UACCESS.

Instead, control them both with CONFIG_ARCH_HAS_PMEM_API so that it's
clear that they are related and we don't run into the possibility where
they are both included or excluded.  Also remove a bunch of stale
function prototypes meant for UM in asm/pmem.h - these just conflicted
with the inline defaults in linux/pmem.h and gave compile errors.

Signed-off-by: Ross Zwisler <19f56ffe3ac18f81d12a74c011e044bc6df12299@linux.intel.com>
Reviewed-by: Christoph Hellwig <923f7720577207a44b32e59bbfbea59d27f1ae8e@lst.de>
Signed-off-by: Dan Williams <24ee2bf0bd8ac766c348bf1f0639943bac1535c6@intel.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs