PCI: Unify PCI and normal DMA direction definitions

Current DMA direction definitions in pci-dma-compat.h and dma-direction.h
are mirrored in value.  Unify them to enhance readability and avoid
possible inconsistency.

Signed-off-by: Shunyong Yang <shunyong.yang@hxt-semitech.com>
Signed-off-by: Bjorn Helgaas <bhelgaas@google.com>
Cc: Joey Zheng <yu.zheng@hxt-semitech.com>
diff --git a/include/linux/dma-direction.h b/include/linux/dma-direction.h
index 3649a03..9c96e30 100644
--- a/include/linux/dma-direction.h
+++ b/include/linux/dma-direction.h
@@ -1,14 +1,12 @@
 /* SPDX-License-Identifier: GPL-2.0 */
 #ifndef _LINUX_DMA_DIRECTION_H
 #define _LINUX_DMA_DIRECTION_H
-/*
- * These definitions mirror those in pci.h, so they can be used
- * interchangeably with their PCI_ counterparts.
- */
+
 enum dma_data_direction {
 	DMA_BIDIRECTIONAL = 0,
 	DMA_TO_DEVICE = 1,
 	DMA_FROM_DEVICE = 2,
 	DMA_NONE = 3,
 };
+
 #endif