ion: Fix sparse non static symbol warnings

Fixes the following sparse warnings:

drivers/staging/android/ion/ion_dummy_driver.c:26:19: warning: symbol 'idev' was not declared. Should it be static?
drivers/staging/android/ion/ion_dummy_driver.c:27:17: warning: symbol 'heaps' was not declared. Should it be static?
drivers/staging/android/ion/ion_dummy_driver.c:29:6: warning: symbol 'carveout_ptr' was not declared. Should it be static?
drivers/staging/android/ion/ion_dummy_driver.c:30:6: warning: symbol 'chunk_ptr' was not declared. Should it be static?
drivers/staging/android/ion/ion_dummy_driver.c:32:26: warning: symbol 'dummy_heaps' was not declared. Should it be static?
drivers/staging/android/ion/ion_dummy_driver.c:59:26: warning: symbol 'dummy_ion_pdata' was not declared. Should it be static?
Signed-off-by: Wei Yongjun <yongjun_wei@trendmicro.com.cn>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/android/ion/ion_dummy_driver.c

@@ -23,13 +23,13 @@
 #include "ion.h"
 #include "ion_priv.h"
 
-struct ion_device *idev;
-struct ion_heap **heaps;
+static struct ion_device *idev;
+static struct ion_heap **heaps;
 
-void *carveout_ptr;
-void *chunk_ptr;
+static void *carveout_ptr;
+static void *chunk_ptr;
 
-struct ion_platform_heap dummy_heaps[] = {
+static struct ion_platform_heap dummy_heaps[] = {
 		{
 			.id	= ION_HEAP_TYPE_SYSTEM,
 			.type	= ION_HEAP_TYPE_SYSTEM,
@@ -56,7 +56,7 @@ struct ion_platform_heap dummy_heaps[] = {
 		},
 };
 
-struct ion_platform_data dummy_ion_pdata = {
+static struct ion_platform_data dummy_ion_pdata = {
 	.nr = 4,
 	.heaps = dummy_heaps,
 };