The SUPPORT_SYSRQ ifdeffery is not nice as:
- May create misunderstanding about sizeof(struct uart_port) between
  different objects
- Prevents moving functions from serial_core.h
- Reduces readability (well, it's ifdeffery - it's hard to follow)
In order to remove SUPPORT_SYSRQ, has_sysrq variable has been added.
Initialise it in driver's probe and remove ifdeffery.
Cc: Patrice Chotard <patrice.chotard@st.com>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Dmitry Safonov <dima@arista.com>
Link: https://lore.kernel.org/r/20191213000657.931618-44-dima@arista.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
  * Copyright (C) 2003-2013 STMicroelectronics (R&D) Limited
  */
 
-#if defined(CONFIG_SERIAL_ST_ASC_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
-#define SUPPORT_SYSRQ
-#endif
-
 #include <linux/module.h>
 #include <linux/serial.h>
 #include <linux/console.h>
        port->fifosize  = ASC_FIFO_SIZE;
        port->dev       = &pdev->dev;
        port->irq       = platform_get_irq(pdev, 0);
+       port->has_sysrq = IS_ENABLED(CONFIG_SERIAL_ST_ASC_CONSOLE);
 
        res = platform_get_resource(pdev, IORESOURCE_MEM, 0);
        port->membase = devm_ioremap_resource(&pdev->dev, res);