staging: i4l: pcbit: replace some include asm/*.h with linux/*.h

Fixes the following checkpatch output:

./pcbit/capi.c:39: WARNING: Use #include <linux/io.h> instead of <asm/io.h>
./pcbit/capi.c:40: WARNING: Use #include <linux/string.h> instead of <asm/string.h>
./pcbit/callbacks.c:25: WARNING: Use #include <linux/io.h> instead of <asm/io.h>
./pcbit/layer2.c:39: WARNING: Use #include <linux/io.h> instead of <asm/io.h>
./pcbit/drv.c:34: WARNING: Use #include <linux/string.h> instead of <asm/string.h>
./pcbit/drv.c:35: WARNING: Use #include <linux/io.h> instead of <asm/io.h>
./pcbit/edss1.c:26: WARNING: Use #include <linux/io.h> instead of <asm/io.h>

Signed-off-by: Alexander Alemayhu <[e-mail]>
Signed-off-by: Greg Kroah-Hartman <[e-mail]>

drivers/staging/i4l/pcbit/callbacks.c

···
 #include <linux/mm.h>
 #include <linux/skbuff.h>
 
-#include <asm/io.h>
+#include <linux/io.h>
 
 #include <linux/isdnif.h>
 

drivers/staging/i4l/pcbit/capi.c

···
 
 #include <linux/skbuff.h>
 
-#include <asm/io.h>
-#include <asm/string.h>
+#include <linux/io.h>
+#include <linux/string.h>
 
 #include <linux/isdnif.h>
 

drivers/staging/i4l/pcbit/drv.c

···
 #include <linux/skbuff.h>
 
 #include <linux/isdnif.h>
-#include <asm/string.h>
-#include <asm/io.h>
+#include <linux/string.h>
+#include <linux/io.h>
 #include <linux/ioport.h>
 
 #include "pcbit.h"

drivers/staging/i4l/pcbit/edss1.c

···
 #include <linux/skbuff.h>
 
 #include <linux/timer.h>
-#include <asm/io.h>
+#include <linux/io.h>
 
 #include <linux/isdnif.h>
 

drivers/staging/i4l/pcbit/layer2.c

···
 
 #include <linux/isdnif.h>
 
-#include <asm/io.h>
+#include <linux/io.h>
 
 
 #include "pcbit.h"