OMAP2 clock: don't compile OMAP2430-only functions on non-2430 builds

omap2430_clk_i2chs_find_idlest() doesn't need to be compiled in on
non-2430 builds, so skip it in those cases to save memory.
Signed-off-by: Paul Walmsley <paul@pwsan.com>

arch/arm/mach-omap2/clock2xxx.c

@@ -50,6 +50,8 @@ struct clk *vclk, *sclk, *dclk;
  * Omap24xx specific clock functions
  *-------------------------------------------------------------------------*/
 
+#ifdef CONFIG_ARCH_OMAP2430
+
 /**
  * omap2430_clk_i2chs_find_idlest - return CM_IDLEST info for 2430 I2CHS
  * @clk: struct clk * being enabled
@@ -69,6 +71,10 @@ static void omap2430_clk_i2chs_find_idlest(struct clk *clk,
 	*idlest_bit = clk->enable_bit;
 }
 
+#else
+#define omap2430_clk_i2chs_find_idlest	NULL
+#endif
+
 /* 2430 I2CHS has non-standard IDLEST register */
 const struct clkops clkops_omap2430_i2chs_wait = {
 	.enable		= omap2_dflt_clk_enable,