video: fbdev: Set pixclock = 0 in goldfishfb

BugLink: https://bugs.launchpad.net/bugs/1826212

[ Upstream commit ace6033e ]

User space Android code identifies pixclock == 0 as a sign for emulation
and will set the frame rate to 60 fps when reading this value, which is
the desired outcome.
Signed-off-by: Christoffer Dall <christoffer.dall@linaro.org>
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
Signed-off-by: Roman Kiryanov <rkir@google.com>
Signed-off-by: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

drivers/video/fbdev/goldfishfb.c

@@ -234,7 +234,7 @@ static int goldfish_fb_probe(struct platform_device *pdev)
 	fb->fb.var.activate	= FB_ACTIVATE_NOW;
 	fb->fb.var.height	= readl(fb->reg_base + FB_GET_PHYS_HEIGHT);
 	fb->fb.var.width	= readl(fb->reg_base + FB_GET_PHYS_WIDTH);
-	fb->fb.var.pixclock	= 10000;
+	fb->fb.var.pixclock	= 0;
 
 	fb->fb.var.red.offset = 11;
 	fb->fb.var.red.length = 5;