drm/rockchip: dsi: Remove the unused function dsi_update_bits()

The function dsi_update_bits() is defined in the dw-mipi-dsi-rockchip.c
file, but not called elsewhere, so delete this unused function.

drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c:367:20: warning: unused function 'dsi_update_bits'.

https://bugzilla.openanolis.cn/show_bug.cgi?id=2414

Reported-by: Abaci Robot <abaci@linux.alibaba.com>
Signed-off-by: Jiapeng Chong <jiapeng.chong@linux.alibaba.com>
Signed-off-by: Heiko Stuebner <heiko@sntech.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20221017084330.94117-1-jiapeng.chong@linux.alibaba.com

drivers/gpu/drm/rockchip/dw-mipi-dsi-rockchip.c

@@ -364,12 +364,6 @@ static inline u32 dsi_read(struct dw_mipi_dsi_rockchip *dsi, u32 reg)
 	return readl(dsi->base + reg);
 }
 
-static inline void dsi_update_bits(struct dw_mipi_dsi_rockchip *dsi, u32 reg,
-				   u32 mask, u32 val)
-{
-	dsi_write(dsi, reg, (dsi_read(dsi, reg) & ~mask) | val);
-}
-
 static void dw_mipi_dsi_phy_write(struct dw_mipi_dsi_rockchip *dsi,
 				  u8 test_code,
 				  u8 test_data)