MAINTAINERS: Update DW 8250 UART maintainership

Add myself as maintainer for DW 8250 UART and up it to Supported.
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Andy Shevchenko <andy.shevchenko@gmail.com>
Acked-by: From: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Link: https://lore.kernel.org/r/be58b398-71ff-7c12-1bf1-a09181d9c80@linux.intel.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

MAINTAINERS

@@ -19249,8 +19249,9 @@ F:	Documentation/devicetree/bindings/gpio/snps,creg-gpio.txt
 F:	drivers/gpio/gpio-creg-snps.c
 
 SYNOPSYS DESIGNWARE 8250 UART DRIVER
+M:	Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
 R:	Andy Shevchenko <andriy.shevchenko@linux.intel.com>
-S:	Maintained
+S:	Supported
 F:	drivers/tty/serial/8250/8250_dw.c
 F:	drivers/tty/serial/8250/8250_dwlib.*
 F:	drivers/tty/serial/8250/8250_lpss.c