PM / devfreq: rockchip-dfi: Clean up DDR type register defines

PM / devfreq: rockchip-dfi: Clean up DDR type register defines

Use the HIWORD_UPDATE() define known from other rockchip drivers to
make the defines look less odd to the readers who've seen other
rockchip drivers.

The HIWORD registers have their functional bits in the lower 16 bits
whereas the upper 16 bits contain a mask. Only the functional bits that
have the corresponding mask bit set are modified during a write. Although
the register writes look different, the end result should be the same,
at least there's no functional change intended with this patch.

Link: https://lore.kernel.org/all/20231018061714.3553817-10-s.hauer@pengutronix.de/
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Reviewed-by: Sebastian Reichel <sebastian.reichel@collabora.com>
Acked-by: Chanwoo Choi <cw00.choi@samsung.com>
Signed-off-by: Chanwoo Choi <cw00.choi@samsung.com>