common: Move reset_phy() to net.h

This is a network function so let's move it into that header.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/include/common.h b/include/common.h
index 1bd4229..eb6dce4 100644
--- a/include/common.h
+++ b/include/common.h
@@ -87,9 +87,6 @@
 long	get_ram_size  (long *, long);
 phys_size_t get_effective_memsize(void);
 
-/* $(BOARD)/$(BOARD).c */
-void	reset_phy     (void);
-
 #if !defined(CONFIG_ENV_EEPROM_IS_ON_I2C) && defined(CONFIG_SYS_I2C_EEPROM_ADDR)
 # define CONFIG_SYS_DEF_EEPROM_ADDR CONFIG_SYS_I2C_EEPROM_ADDR
 #endif
diff --git a/include/net.h b/include/net.h
index a8ee081..8a02c92 100644
--- a/include/net.h
+++ b/include/net.h
@@ -917,4 +917,12 @@
 {
 	return string_to_ip(env_get(var));
 }
+
+/**
+ * reset_phy() - Reset the Ethernet PHY
+ *
+ * This should be implemented by boards if CONFIG_RESET_PHY_R is enabled
+ */
+void reset_phy(void);
+
 #endif /* __NET_H__ */