stm class: sys-t: Fix the use of time_after()

stm class: sys-t: Fix the use of time_after()

The operands of time_after() are in a wrong order in both instances in
the sys-t driver. Fix that.

Signed-off-by: Alexander Shishkin <alexander.shishkin@linux.intel.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Fixes: 279905a031f8 ("stm class: p_sys-t: Add support for CLOCKSYNC packets")
Fixes: 506d2d2270f7 ("stm class: Add MIPI SyS-T protocol support")
Cc: stable@vger.kernel.org # v4.20+
Link: https://lore.kernel.org/r/20200317062215.15598-3-alexander.shishkin@linux.intel.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>