bus: mvebu-mbus: use DEFINE_SHOW_ATTRIBUTE to simplify mvebu_{sdram/devs}_debug

Use DEFINE_SHOW_ATTRIBUTE helper macro to simplify the code.
Signed-off-by: Liu Shixin <liushixin2@huawei.com>
Link: https://lore.kernel.org/r/20220916141244.2174005-1-liushixin2@huawei.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/bus/mvebu-mbus.c

@@ -466,18 +466,7 @@ static int mvebu_sdram_debug_show(struct seq_file *seq, void *v)
 	struct mvebu_mbus_state *mbus = &mbus_state;
 	return mbus->soc->show_cpu_target(mbus, seq, v);
 }
-
-static int mvebu_sdram_debug_open(struct inode *inode, struct file *file)
-{
-	return single_open(file, mvebu_sdram_debug_show, inode->i_private);
-}
-
-static const struct file_operations mvebu_sdram_debug_fops = {
-	.open = mvebu_sdram_debug_open,
-	.read = seq_read,
-	.llseek = seq_lseek,
-	.release = single_release,
-};
+DEFINE_SHOW_ATTRIBUTE(mvebu_sdram_debug);
 
 static int mvebu_devs_debug_show(struct seq_file *seq, void *v)
 {
@@ -516,18 +505,7 @@ static int mvebu_devs_debug_show(struct seq_file *seq, void *v)
 
 	return 0;
 }
-
-static int mvebu_devs_debug_open(struct inode *inode, struct file *file)
-{
-	return single_open(file, mvebu_devs_debug_show, inode->i_private);
-}
-
-static const struct file_operations mvebu_devs_debug_fops = {
-	.open = mvebu_devs_debug_open,
-	.read = seq_read,
-	.llseek = seq_lseek,
-	.release = single_release,
-};
+DEFINE_SHOW_ATTRIBUTE(mvebu_devs_debug);
 
 /*
  * SoC-specific functions and definitions