dm: core: Introduce xxx_translate_dma_address()

Add the following functions to translate DMA address to CPU address:
- dev_translate_dma_address()
- ofnode_translate_dma_address()
- of_translate_dma_address()
- fdt_translate_dma_address()
These functions work the same way as xxx_translate_address(), with the
difference that the translation relies on the "dma-ranges" property
instead of the "ranges" property.

Add related test. Test report:
=> ut dm fdt_translation
Test: dm_test_fdt_translation: test-fdt.c
Test: dm_test_fdt_translation: test-fdt.c (flat tree)
Failures: 0

Signed-off-by: Fabien Dessenne <fabien.dessenne@st.com>
diff --git a/test/dm/test-fdt.c b/test/dm/test-fdt.c
index be16c99..ad85916 100644
--- a/test/dm/test-fdt.c
+++ b/test/dm/test-fdt.c
@@ -490,6 +490,7 @@
 static int dm_test_fdt_translation(struct unit_test_state *uts)
 {
 	struct udevice *dev;
+	fdt32_t dma_addr[2];
 
 	/* Some simple translations */
 	ut_assertok(uclass_find_device_by_seq(UCLASS_TEST_DUMMY, 0, true, &dev));
@@ -509,6 +510,17 @@
 	ut_asserteq_str("dev@42", dev->name);
 	ut_asserteq(0x42, dev_read_addr(dev));
 
+	/* dma address translation */
+	ut_assertok(uclass_find_device_by_seq(UCLASS_TEST_DUMMY, 0, true, &dev));
+	dma_addr[0] = cpu_to_be32(0);
+	dma_addr[1] = cpu_to_be32(0);
+	ut_asserteq(0x10000000, dev_translate_dma_address(dev, dma_addr));
+
+	ut_assertok(uclass_find_device_by_seq(UCLASS_TEST_DUMMY, 1, true, &dev));
+	dma_addr[0] = cpu_to_be32(1);
+	dma_addr[1] = cpu_to_be32(0x100);
+	ut_asserteq(0x20000000, dev_translate_dma_address(dev, dma_addr));
+
 	return 0;
 }
 DM_TEST(dm_test_fdt_translation, DM_TESTF_SCAN_PDATA | DM_TESTF_SCAN_FDT);