OMAP powerdomain: remove pwrdm_clk_state_switch

Nothing calls pwrdm_clk_state_switch(), and the function that seems to be
its ideal use case calls pwrdm_clkdm_state_switch(clk->clkdm), so remove it.
Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Tero Kristo <tero.kristo@nokia.com>
Cc: Kevin Hilman <khilman@deeprootsystems.com>

arch/arm/mach-omap2/powerdomain.c

@@ -928,12 +928,6 @@ int pwrdm_clkdm_state_switch(struct clockdomain *clkdm)
 
 	return -EINVAL;
 }
-int pwrdm_clk_state_switch(struct clk *clk)
-{
-	if (clk != NULL && clk->clkdm != NULL)
-		return pwrdm_clkdm_state_switch(clk->clkdm);
-	return -EINVAL;
-}
 
 int pwrdm_pre_transition(void)
 {