tty: serial: fsl_lpuart: increase maximum uart_nr to 12

Some SoCs like the i.MX943 have aliases for up to 12 UARTs, need to
increase UART_NR from 8 to 12 to support lpuart9-12 to avoid
initialization failures.

Signed-off-by: Sherry Sun <sherry.sun@nxp.com>
Link: https://lore.kernel.org/r/20250103071154.3070924-1-sherry.sun@nxp.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: SherrySun5

drivers/tty/serial/fsl_lpuart.c

@@ -245,7 +245,7 @@
 
 #define DRIVER_NAME	"fsl-lpuart"
 #define DEV_NAME	"ttyLP"
-#define UART_NR		8
+#define UART_NR		12
 
 /* IMX lpuart has four extra unused regs located at the beginning */
 #define IMX_REG_OFF	0x10