regmap: Fix leftover from struct reg_default to struct reg_sequence change

In 8019ff6c ("regmap: Use reg_sequence for multi_reg_write / register_patch")
struct reg_default was renamed to struct reg_secquence, which missed
one place to fix up.

Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Daniel Wagner <daniel.wagner@bmw-carit.de>
Signed-off-by: Mark Brown <broonie@kernel.org>