drm/arm: make undeclared items static

Make the following items static to avoid clashes with
other parts of the kernel (dev_attr_core_id) or just
silence the following sparse warning:

drivers/gpu/drm/arm/malidp_drv.c:371:24: warning: symbol 'malidp_fb_create' was not declared. Should it be static?
drivers/gpu/drm/arm/malidp_drv.c:494:6: warning: symbol 'malidp_error_stats_dump' was not declared. Should it be static?
drivers/gpu/drm/arm/malidp_drv.c:668:1: warning: symbol 'dev_attr_core_id' was not declared. Should it be static?

Signed-off-by: Ben Dooks (Codethink) <[e-mail]>
Signed-off-by: Liviu Dudau <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/arm/malidp_drv.c

···
 	return false;
 }
 
-struct drm_framebuffer *
+static struct drm_framebuffer *
 malidp_fb_create(struct drm_device *dev, struct drm_file *file,
 		 const struct drm_mode_fb_cmd2 *mode_cmd)
 {
···
 	spin_unlock_irqrestore(&malidp->errors_lock, irqflags);
 }
 
-void malidp_error_stats_dump(const char *prefix,
-			     struct malidp_error_stats error_stats,
-			     struct seq_file *m)
+static void malidp_error_stats_dump(const char *prefix,
+				    struct malidp_error_stats error_stats,
+				    struct seq_file *m)
 {
 	seq_printf(m, "[%s] num_errors : %d\n", prefix,
 		   error_stats.num_errors);
···
 	return snprintf(buf, PAGE_SIZE, "%08x\n", malidp->core_id);
 }
 
-DEVICE_ATTR_RO(core_id);
+static DEVICE_ATTR_RO(core_id);
 
 static int malidp_init_sysfs(struct device *dev)
 {