drm/ast: Use msleep instead of mdelay for edid read

The busy-waiting in `mdelay()` can cause CPU stalls and kernel timeouts
during boot.

Signed-off-by: Nirmoy Das <nirmoyd@nvidia.com>
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Tested-by: Carol L Soto csoto@nvidia.com<mailto:csoto@nvidia.com>
Fixes: 594e9c04 ("drm/ast: Create the driver for ASPEED proprietory Display-Port")
Cc: KuoHsiang Chou <kuohsiang_chou@aspeedtech.com>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Dave Airlie <airlied@redhat.com>
Cc: Jocelyn Falempe <jfalempe@redhat.com>
Cc: dri-devel@lists.freedesktop.org
Cc: <stable@vger.kernel.org> # v5.19+
Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://lore.kernel.org/r/20250917194346.2905522-1-nirmoyd@nvidia.com