bus: mvebu-bus: Provide inline stub for mvebu_mbus_get_dram_win_info

In preparation for allowing CONFIG_MVNETA_BM to build with COMPILE_TEST,
provide an inline stub for mvebu_mbus_get_dram_win_info().

Signed-off-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/include/linux/mbus.h b/include/linux/mbus.h
index 2931aa4..0d3f14f 100644
--- a/include/linux/mbus.h
+++ b/include/linux/mbus.h
@@ -82,6 +82,7 @@
 }
 #endif
 
+#ifdef CONFIG_MVEBU_MBUS
 int mvebu_mbus_save_cpu_target(u32 __iomem *store_addr);
 void mvebu_mbus_get_pcie_mem_aperture(struct resource *res);
 void mvebu_mbus_get_pcie_io_aperture(struct resource *res);
@@ -97,5 +98,12 @@
 		    size_t mbus_size, phys_addr_t sdram_phys_base,
 		    size_t sdram_size);
 int mvebu_mbus_dt_init(bool is_coherent);
+#else
+static inline int mvebu_mbus_get_dram_win_info(phys_addr_t phyaddr, u8 *target,
+					       u8 *attr)
+{
+	return -EINVAL;
+}
+#endif /* CONFIG_MVEBU_MBUS */
 
 #endif /* __LINUX_MBUS_H */