ADB: Add missing #include <linux/platform_device.h>

Commit c9f6d3d5c6d4f4cd3a53549a69c92951180e2a76 ("[POWERPC] adb: Replace
sleep notifier with platform driver suspend/resume hooks") introduced
compile errors on m68k because <linux/platform_device.h> is not
explicitly included. On powerpc, it's pulled in through <asm/prom.h>.

Signed-off-by: Geert Uytterhoeven <[e-mail]>
Signed-off-by: Linus Torvalds <[e-mail]>

drivers/macintosh/adb.c

···
 #include <linux/completion.h>
 #include <linux/device.h>
 #include <linux/kthread.h>
+#include <linux/platform_device.h>
 
 #include <asm/uaccess.h>
 #include <asm/semaphore.h>