regcache: use map->alloc_flags also for allocating cache

Commit fd4ebc07b4df ("regmap: Hold the regmap lock when allocating and
freeing the cache") introduced a locking around the allocating and
freeing a regmap cache, so adjust the memory allocation flags to the ones
given in the regmap configuration instead of the hardcoded GFP_KERNEL.

This fixes the "BUG: sleeping function called from invalid context"
introduced by the mentioned commit.

Fixes: fd4ebc07b4df ("regmap: Hold the regmap lock when allocating and freeing the cache")
Signed-off-by: Marek Szyprowski <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Mark Brown <[e-mail]>

drivers/base/regmap/regcache-flat.c

···
 		return -EINVAL;
 
 	map->cache = kcalloc(regcache_flat_get_index(map, map->max_register)
-			     + 1, sizeof(unsigned int), GFP_KERNEL);
+			     + 1, sizeof(unsigned int), map->alloc_flags);
 	if (!map->cache)
 		return -ENOMEM;
 

drivers/base/regmap/regcache-maple.c

···
 	int ret;
 	int range_start;
 
-	mt = kmalloc(sizeof(*mt), GFP_KERNEL);
+	mt = kmalloc(sizeof(*mt), map->alloc_flags);
 	if (!mt)
 		return -ENOMEM;
 	map->cache = mt;

drivers/base/regmap/regcache-rbtree.c

···
 	int i;
 	int ret;
 
-	map->cache = kmalloc(sizeof *rbtree_ctx, GFP_KERNEL);
+	map->cache = kmalloc(sizeof *rbtree_ctx, map->alloc_flags);
 	if (!map->cache)
 		return -ENOMEM;