soc: sophgo: sg2044: Add support for SG2044 TOP syscon device

The SG2044 TOP device provide PLL clock function in its area.
Add a mfd definition for it.

Link: https://lore.kernel.org/r/20250418020325.421257-3-inochiama@gmail.com


Signed-off-by: Inochi Amaoto <inochiama@gmail.com>
Signed-off-by: Chen Wang <unicorn_wang@outlook.com>
Signed-off-by: Chen Wang <wangchen20@iscas.ac.cn>