m68k: Dispatch nvram_ops calls to Atari or Mac functions

A multi-platform kernel binary has to decide at run-time how to dispatch
the arch_nvram_ops calls. Add a platform-independent arch_nvram_ops
struct for this, to replace the atari-specific one.

Enable CONFIG_HAVE_ARCH_NVRAM_OPS for Macs.

Acked-by: Geert Uytterhoeven <geert@linux-m68k.org>
Tested-by: Stan Johnson <userm57@yahoo.com>
Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

arch/m68k/atari/nvram.c

@@ -74,7 +74,7 @@ static void __nvram_set_checksum(void)
 	__nvram_write_byte(sum, ATARI_CKS_LOC + 1);
 }
 
-static long atari_nvram_set_checksum(void)
+long atari_nvram_set_checksum(void)
 {
 	spin_lock_irq(&rtc_lock);
 	__nvram_set_checksum();
@@ -82,7 +82,7 @@ static long atari_nvram_set_checksum(void)
 	return 0;
 }
 
-static long atari_nvram_initialize(void)
+long atari_nvram_initialize(void)
 {
 	loff_t i;
 
@@ -94,7 +94,7 @@ static long atari_nvram_initialize(void)
 	return 0;
 }
 
-static ssize_t atari_nvram_read(char *buf, size_t count, loff_t *ppos)
+ssize_t atari_nvram_read(char *buf, size_t count, loff_t *ppos)
 {
 	char *p = buf;
 	loff_t i;
@@ -112,7 +112,7 @@ static ssize_t atari_nvram_read(char *buf, size_t count, loff_t *ppos)
 	return p - buf;
 }
 
-static ssize_t atari_nvram_write(char *buf, size_t count, loff_t *ppos)
+ssize_t atari_nvram_write(char *buf, size_t count, loff_t *ppos)
 {
 	char *p = buf;
 	loff_t i;
@@ -131,22 +131,11 @@ static ssize_t atari_nvram_write(char *buf, size_t count, loff_t *ppos)
 	return p - buf;
 }
 
-static ssize_t atari_nvram_get_size(void)
+ssize_t atari_nvram_get_size(void)
 {
-	if (!MACH_IS_ATARI)
-		return -ENODEV;
 	return NVRAM_BYTES;
 }
 
-const struct nvram_ops arch_nvram_ops = {
-	.read           = atari_nvram_read,
-	.write          = atari_nvram_write,
-	.get_size       = atari_nvram_get_size,
-	.set_checksum   = atari_nvram_set_checksum,
-	.initialize     = atari_nvram_initialize,
-};
-EXPORT_SYMBOL(arch_nvram_ops);
-
 #ifdef CONFIG_PROC_FS
 static struct {
 	unsigned char val;