tty/serial: Migrate amba-pl01* to use has_sysrq

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: Russell King <linux@armlinux.org.uk>
Signed-off-by: Dmitry Safonov <dima@arista.com>
Link: https://lore.kernel.org/r/20191213000657.931618-10-dima@arista.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/tty/serial/amba-pl010.c

@@ -15,10 +15,6 @@
  * and hooked into this driver.
  */
 
-#if defined(CONFIG_SERIAL_AMBA_PL010_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
-#define SUPPORT_SYSRQ
-#endif
-
 #include <linux/module.h>
 #include <linux/ioport.h>
 #include <linux/init.h>
@@ -728,6 +724,7 @@ static int pl010_probe(struct amba_device *dev, const struct amba_id *id)
 	uap->port.iotype = UPIO_MEM;
 	uap->port.irq = dev->irq[0];
 	uap->port.fifosize = 16;
+	uap->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_AMBA_PL010_CONSOLE);
 	uap->port.ops = &amba_pl010_pops;
 	uap->port.flags = UPF_BOOT_AUTOCONF;
 	uap->port.line = i;

drivers/tty/serial/amba-pl011.c

@@ -16,11 +16,6 @@
  * and hooked into this driver.
  */
 
-
-#if defined(CONFIG_SERIAL_AMBA_PL011_CONSOLE) && defined(CONFIG_MAGIC_SYSRQ)
-#define SUPPORT_SYSRQ
-#endif
-
 #include <linux/module.h>
 #include <linux/ioport.h>
 #include <linux/init.h>
@@ -2577,6 +2572,7 @@ static int pl011_setup_port(struct device *dev, struct uart_amba_port *uap,
 	uap->port.mapbase = mmiobase->start;
 	uap->port.membase = base;
 	uap->port.fifosize = uap->fifosize;
+	uap->port.has_sysrq = IS_ENABLED(CONFIG_SERIAL_AMBA_PL011_CONSOLE);
 	uap->port.flags = UPF_BOOT_AUTOCONF;
 	uap->port.line = index;