clk: mmp2: Remove a unused prototype

There is no mmp_clk_register_pll2() routine.
Signed-off-by: Lubomir Rintel <lkundrak@v3.sk>
Link: https://lkml.kernel.org/r/20200309194254.29009-2-lkundrak@v3.skSigned-off-by: Stephen Boyd <sboyd@kernel.org>

drivers/clk/mmp/clk.h

@@ -124,9 +124,6 @@ extern struct clk *mmp_clk_register_gate(struct device *dev, const char *name,
 			u32 val_disable, unsigned int gate_flags,
 			spinlock_t *lock);
 
-
-extern struct clk *mmp_clk_register_pll2(const char *name,
-		const char *parent_name, unsigned long flags);
 extern struct clk *mmp_clk_register_apbc(const char *name,
 		const char *parent_name, void __iomem *base,
 		unsigned int delay, unsigned int apbc_flags, spinlock_t *lock);