MIPS: AR7: Normalize clk API

Coldfire still provides its own variant of the clk API rather than using
the generic COMMON_CLK API.  This generally works, but it causes some
link errors with drivers using the clk_round_rate(), clk_set_rate(),
clk_set_parent(), or clk_get_parent() functions when a platform lacks
those interfaces.

This adds empty stub implementations for each of them, and I don't even
try to do something useful here but instead just print a WARN() message
to make it obvious what is going on if they ever end up being called.

The drivers that call these won't be used on these platforms (otherwise
we'd get a link error today), so the added code is harmless bloat and
will warn about accidental use.

Based on commit bd7fefe1 ("ARM: w90x900: normalize clk API").
Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Signed-off-by: Paul Burton <paul.burton@mips.com>
Patchwork: https://patchwork.linux-mips.org/patch/19503/
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: linux-m68k@lists.linux-m68k.org
Cc: linux-mips@linux-mips.org
Cc: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org

arch/mips/ar7/clock.c

@@ -476,3 +476,32 @@ void __init ar7_init_clocks(void)
 	/* adjust vbus clock rate */
 	vbus_clk.rate = bus_clk.rate / 2;
 }
+
+/* dummy functions, should not be called */
+long clk_round_rate(struct clk *clk, unsigned long rate)
+{
+	WARN_ON(clk);
+	return 0;
+}
+EXPORT_SYMBOL(clk_round_rate);
+
+int clk_set_rate(struct clk *clk, unsigned long rate)
+{
+	WARN_ON(clk);
+	return 0;
+}
+EXPORT_SYMBOL(clk_set_rate);
+
+int clk_set_parent(struct clk *clk, struct clk *parent)
+{
+	WARN_ON(clk);
+	return 0;
+}
+EXPORT_SYMBOL(clk_set_parent);
+
+struct clk *clk_get_parent(struct clk *clk)
+{
+	WARN_ON(clk);
+	return NULL;
+}
+EXPORT_SYMBOL(clk_get_parent);