drm/rockchip: avoid 64-bit division

Dividing a 64-bit integer prevents building this for 32-bit targets:

ERROR: modpost: "__aeabi_uldivmod" [drivers/gpu/drm/rockchip/rockchipdrm.ko] undefined!

As this function is not performance criticial, just Use the div_u64() helper.

Fixes: 128a9bf ("drm/rockchip: Add basic RK3588 HDMI output support")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Dmitry Baryshkov <dmitry.baryshkov@linaro.org>
Reviewed-by: Nathan Chancellor <nathan@kernel.org>
Link: https://lore.kernel.org/r/20241018151016.3496613-1-arnd@kernel.org
Signed-off-by: Liviu Dudau <liviu.dudau@arm.com>
(cherry picked from commit 4b64b4a)
Signed-off-by: Maxime Ripard <mripard@kernel.org>

Author: arndb

drivers/gpu/drm/rockchip/dw_hdmi_qp-rockchip.c

@@ -82,7 +82,7 @@ static void dw_hdmi_qp_rockchip_encoder_enable(struct drm_encoder *encoder)
 		 * comment in rk_hdptx_phy_power_on() from
 		 * drivers/phy/rockchip/phy-rockchip-samsung-hdptx.c
 		 */
-		phy_set_bus_width(hdmi->phy, rate / 100);
+		phy_set_bus_width(hdmi->phy, div_u64(rate, 100));
 	}
 }