drivers/nvdimm: Use local kmaps

drivers/nvdimm: Use local kmaps

Replace the now deprecated kmap_atomic() with kmap_local_page().

Optimizing nvdimm/pmem for highmem makes no sense as this is always
64bit, and the mapped regions for both btt and pmem do not require
disabling preemption and pagefaults. Specifically, kmap does not care
about the caller's atomic context (such as reads holding the btt arena
spinlock) or NVDIMM_IO_ATOMIC semantics to avoid error handling when
accessing the btt arena in general. Same for the memcpy cases. kmap
local temporary mappings will hold valid across any context switches.

Signed-off-by: Davidlohr Bueso <dave@stgolabs.net>
Reviewed-by: Dave Jiang <dave.jiang@intel.com>> ---
Link: https://patch.msgid.link/20251128212303.2170933-1-dave@stgolabs.net
Signed-off-by: Ira Weiny <ira.weiny@intel.com>