of: introduce of_dma_get_range() helper

The of_dma_get_range() allows to find "dma-range" property for
the specified device and parse it.
 dma-ranges format:
   DMA addr (dma_addr)          : naddr cells
   CPU addr (phys_addr_t)       : pna cells
   size                         : nsize cells

Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Olof Johansson <olof@lixom.net>
Cc: Grant Likely <grant.likely@linaro.org>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
diff --git a/include/linux/of_address.h b/include/linux/of_address.h
index 5f6ed6b..4d7b325 100644
--- a/include/linux/of_address.h
+++ b/include/linux/of_address.h
@@ -63,6 +63,8 @@
 extern struct of_pci_range *of_pci_range_parser_one(
 					struct of_pci_range_parser *parser,
 					struct of_pci_range *range);
+extern int of_dma_get_range(struct device_node *np, u64 *dma_addr,
+				u64 *paddr, u64 *size);
 #else /* CONFIG_OF_ADDRESS */
 static inline struct device_node *of_find_matching_node_by_address(
 					struct device_node *from,
@@ -90,6 +92,12 @@
 {
 	return NULL;
 }
+
+static inline int of_dma_get_range(struct device_node *np, u64 *dma_addr,
+				u64 *paddr, u64 *size)
+{
+	return -ENODEV;
+}
 #endif /* CONFIG_OF_ADDRESS */
 
 #ifdef CONFIG_OF