x86: remove dead code in intel_clk_get_rate()

If all branches of a switch statement have a return instruction, all
subsequent lines are unreachable.

Identified with cppcheck.

Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Reviewed-by: Lukasz Majewski <lukma@denx.de>
Reviewed-by: Simon Glass <sjg@chromium.org>

drivers/clk/intel/clk_intel.c

@@ -11,8 +11,6 @@
 
 static ulong intel_clk_get_rate(struct clk *clk)
 {
-	ulong rate;
-
 	switch (clk->id) {
 	case CLK_I2C:
 		/* Hard-coded to 133MHz on current platforms */
@@ -20,8 +18,6 @@ static ulong intel_clk_get_rate(struct clk *clk)
 	default:
 		return -ENODEV;
 	}
-
-	return rate;
 }
 
 static struct clk_ops intel_clk_ops = {