UPSTREAM: regmap: fix deadlock on _regmap_raw_write() error path

UPSTREAM: regmap: fix deadlock on _regmap_raw_write() error path

Commit 815806e39bf6 ("regmap: drop cache if the bus transfer error")
added a call to regcache_drop_region() to error path in
_regmap_raw_write(). However that path runs with regmap lock taken,
and regcache_drop_region() tries to re-take it, causing a deadlock.
Fix that by calling map->cache_ops->drop() directly.

Change-Id: I55c6d3ed490c47e8b3f5ca774d051a700f707b6e
Signed-off-by: Nikita Yushchenko <nikita.yoush@cogentembedded.com>
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Huang, Tao <huangtao@rock-chips.com>
(cherry picked from git.kernel.org broonie/regmap.git for-next
 commit f0aa1ce6259eb65f53f969b3250c1d0aac84f30b)