drm/msm/dsi: fix 32-bit signed integer extension in pclk_rate calculation

When (mode->clock * 1000) is larger than (1<<31), int to unsigned long
conversion will sign extend the int to 64 bits and the pclk_rate value
will be incorrect.

Fix this by making the result of the multiplication unsigned.

Note that above (1<<32) would still be broken and require more changes, but
its unlikely anyone will need that anytime soon.

Fixes: c4d8cfe516dc ("drm/msm/dsi: add implementation for helper functions")
Signed-off-by: Jonathan Marek <[e-mail]>
Reviewed-by: Dmitry Baryshkov <[e-mail]>
Reviewed-by: Abhinav Kumar <[e-mail]>
Patchwork: https://patchwork.freedesktop.org/patch/618434/
Link: https://lore.kernel.org/r/[e-mail]
Signed-off-by: Abhinav Kumar <[e-mail]>

drivers/gpu/drm/msm/dsi/dsi_host.c

···
 {
 	unsigned long pclk_rate;
 
-	pclk_rate = mode->clock * 1000;
+	pclk_rate = mode->clock * 1000u;
 
 	if (dsc)
 		pclk_rate = dsi_adjust_pclk_for_compression(mode, dsc);