m68k: Prevent some compiler warnings in Coldfire builds

Since commit d3b41b6bb4 ("m68k: Dispatch nvram_ops calls to Atari or
Mac functions"), Coldfire builds generate compiler warnings due to the
unconditional inclusion of asm/atarihw.h and asm/macintosh.h.

The inclusion of asm/atarihw.h causes warnings like this:

In file included from ./arch/m68k/include/asm/atarihw.h:25:0,
                 from arch/m68k/kernel/setup_mm.c:41,
                 from arch/m68k/kernel/setup.c:3:
./arch/m68k/include/asm/raw_io.h:39:0: warning: "__raw_readb" redefined
 #define __raw_readb in_8

In file included from ./arch/m68k/include/asm/io.h:6:0,
                 from arch/m68k/kernel/setup_mm.c:36,
                 from arch/m68k/kernel/setup.c:3:
./arch/m68k/include/asm/io_no.h:16:0: note: this is the location of the previous definition
 #define __raw_readb(addr) \
...

This issue is resolved by dropping the asm/raw_io.h include. It turns out
that asm/io_mm.h already includes that header file.

Moving the relevant macro definitions helps to clarify this dependency
and make it safe to include asm/atarihw.h.

The other warnings look like this:

In file included from arch/m68k/kernel/setup_mm.c:48:0,
                 from arch/m68k/kernel/setup.c:3:
./arch/m68k/include/asm/macintosh.h:19:35: warning: 'struct irq_data' declared inside parameter list will not be visible outside of this definition or declaration
 extern void mac_irq_enable(struct irq_data *data);
                                   ^~~~~~~~
...

This issue is resolved by adding the missing linux/irq.h include.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Acked-by: Greg Ungerer <gerg@linux-m68k.org>
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>

arch/m68k/include/asm/io_mm.h

@@ -29,7 +29,11 @@
 #include <asm-generic/iomap.h>
 
 #ifdef CONFIG_ATARI
-#include <asm/atarihw.h>
+#define atari_readb   raw_inb
+#define atari_writeb  raw_outb
+
+#define atari_inb_p   raw_inb
+#define atari_outb_p  raw_outb
 #endif