serial: imx: change SERIAL_IMX_CONSOLE to bool

SERIAL_IMX_CONSOLE is a build option for the imx driver (SERIAL_IMX).
It does not build a separate console driver file, so it can't be built
as a module since it isn't built at all.

Change the Kconfig symbol from tristate to bool and update the help
text accordingly.

Fixes: 0db4f9b ("tty: serial: imx: enable imx serial console port as module")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Link: https://patch.msgid.link/20260110232643.3533351-2-rdunlap@infradead.org
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: rddunlap

drivers/tty/serial/Kconfig

@@ -486,14 +486,14 @@ config SERIAL_IMX
 	  can enable its onboard serial port by enabling this option.
 
 config SERIAL_IMX_CONSOLE
-	tristate "Console on IMX serial port"
+	bool "Console on IMX serial port"
 	depends on SERIAL_IMX
 	select SERIAL_CORE_CONSOLE
 	help
 	  If you have enabled the serial port on the Freescale IMX
-	  CPU you can make it the console by answering Y/M to this option.
+	  CPU you can make it the console by answering Y to this option.
 
-	  Even if you say Y/M here, the currently visible virtual console
+	  Even if you say Y here, the currently visible virtual console
 	  (/dev/tty0) will still be used as the system console by default, but
 	  you can alter that using a kernel command line option such as
 	  "console=ttymxc0". (Try "man bootparam" or see the documentation of