sh: landisk: Add missing initialization of sh_io_port_base

The Landisk setup code maps the CF IDE area using ioremap_prot(), and
passes the resulting virtual addresses to the pata_platform driver,
disguising them as I/O port addresses.  Hence the pata_platform driver
translates them again using ioport_map().
As CONFIG_GENERIC_IOMAP=n, and CONFIG_HAS_IOPORT_MAP=y, the
SuperH-specific mapping code in arch/sh/kernel/ioport.c translates
I/O port addresses to virtual addresses by adding sh_io_port_base, which
defaults to -1, thus breaking the assumption of an identity mapping.

Fix this by setting sh_io_port_base to zero.

Fixes: 37b7a978 ("sh: machvec IO death.")
Signed-off-by: Geert Uytterhoeven <geert+renesas@glider.be>
Signed-off-by: Rich Felker <dalias@libc.org>

arch/sh/boards/mach-landisk/setup.c

@@ -82,6 +82,9 @@ device_initcall(landisk_devices_setup);
 
 static void __init landisk_setup(char **cmdline_p)
 {
+	/* I/O port identity mapping */
+	__set_io_port_base(0);
+
 	/* LED ON */
 	__raw_writeb(__raw_readb(PA_LED) | 0x03, PA_LED);