auxdisplay: charlcd: Add missing MODULE_DESCRIPTION()

The modpost script is not happy

  WARNING: modpost: missing MODULE_DESCRIPTION() in drivers/auxdisplay/charlcd.o

because there is a missing module description.

Add it to the module.

Reviewed-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>