serial: omap: drop "inline" from IRQ handler prototype

it makes no sense to mark our IRQ handler inline
since it's passed as a function pointer when
enabling the IRQ line.
Tested-by: NShubhrajyoti D <shubhrajyoti@ti.com>
Signed-off-by: NFelipe Balbi <balbi@ti.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/omap-serial.c

@@ -345,7 +345,7 @@ static void serial_omap_rdi(struct uart_omap_port *up, unsigned int lsr)
  * @irq: uart port irq number
  * @dev_id: uart port info
  */
-static inline irqreturn_t serial_omap_irq(int irq, void *dev_id)
+static irqreturn_t serial_omap_irq(int irq, void *dev_id)
 {
 	struct uart_omap_port *up = dev_id;
 	struct tty_struct *tty = up->port.state->port.tty;