mei: vsc: Prevent timeout error with added delay post-firmware download

mei: vsc: Prevent timeout error with added delay post-firmware download

After completing the firmware download, the firmware requires some
time to become functional. This change introduces additional sleep
time before the first read operation to prevent a confusing timeout
error in vsc_tp_xfer().

Fixes: 566f5ca97680 ("mei: Add transport driver for IVSC device")
Cc: stable@vger.kernel.org # for 6.8+
Signed-off-by: Wentong Wu <wentong.wu@intel.com>
Tested-by: Jason Chen <jason.z.chen@intel.com>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Link: https://lore.kernel.org/r/20240625081047.4178494-3-wentong.wu@intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>