drm/radeon/kms: fix bad shift in atom iio table parser

Noticed by Patrick Lowry.
Signed-off-by: NAlex Deucher <alexdeucher@gmail.com>
Cc: stable@kernel.org
Signed-off-by: NDave Airlie <airlied@redhat.com>

drivers/gpu/drm/radeon/atom.c

@@ -135,7 +135,7 @@ static uint32_t atom_iio_execute(struct atom_context *ctx, int base,
 		case ATOM_IIO_MOVE_INDEX:
 			temp &=
 			    ~((0xFFFFFFFF >> (32 - CU8(base + 1))) <<
-			      CU8(base + 2));
+			      CU8(base + 3));
 			temp |=
 			    ((index >> CU8(base + 2)) &
 			     (0xFFFFFFFF >> (32 - CU8(base + 1)))) << CU8(base +
@@ -145,7 +145,7 @@ static uint32_t atom_iio_execute(struct atom_context *ctx, int base,
 		case ATOM_IIO_MOVE_DATA:
 			temp &=
 			    ~((0xFFFFFFFF >> (32 - CU8(base + 1))) <<
-			      CU8(base + 2));
+			      CU8(base + 3));
 			temp |=
 			    ((data >> CU8(base + 2)) &
 			     (0xFFFFFFFF >> (32 - CU8(base + 1)))) << CU8(base +
@@ -155,7 +155,7 @@ static uint32_t atom_iio_execute(struct atom_context *ctx, int base,
 		case ATOM_IIO_MOVE_ATTR:
 			temp &=
 			    ~((0xFFFFFFFF >> (32 - CU8(base + 1))) <<
-			      CU8(base + 2));
+			      CU8(base + 3));
 			temp |=
 			    ((ctx->
 			      io_attr >> CU8(base + 2)) & (0xFFFFFFFF >> (32 -