tty: serial: sh-sci: Hide number of ports config question

Auto-configure the maximum number of serial ports based on how many can
be present on the architecture:
  - 3 on H8/300,
  - 10 on SuperH,
  - 18 on Reneas ARM.

The default can still be overridden if CONFIG_EXPERT is enabled.
Signed-off-by: NGeert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/Kconfig

@@ -761,9 +761,11 @@ config SERIAL_SH_SCI
 	select SERIAL_MCTRL_GPIO if GPIOLIB
 
 config SERIAL_SH_SCI_NR_UARTS
-	int "Maximum number of SCI(F) serial ports"
+	int "Maximum number of SCI(F) serial ports" if EXPERT
 	depends on SERIAL_SH_SCI
-	default "2"
+	default "3" if H8300
+	default "10" if SUPERH
+	default "18" if ARCH_RENESAS
 
 config SERIAL_SH_SCI_CONSOLE
 	bool "Support for console on SuperH SCI(F)"