ASoC: OMAP: fix OMAP1 compilation problem

In the new code introduced with commit cf4c87ab,
"OMAP: McBSP: implement McBSP CLKR and FSR signal muxing via mach-omap2/mcbsp.c",
the way omap1 build is supposed to bypass omap2 specific functionality doesn't
optimize out all omap2 specific stuff. This breaks linking phase for omap1
machines, giving "undefined reference to `omap2_mcbsp1_mux_clkr_src'"
and "undefined reference to `omap2_mcbsp1_mux_fsr_src'" errors. Fix it.

Created and tested against linux-2.6.37-rc1.
Signed-off-by: Janusz Krzysztofik <jkrzyszt@tis.icnet.pl>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Paul Walmsley <paul@pwsan.com>
Acked-by: Jarkko Nikula <jhnikula@gmail.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>

sound/soc/omap/omap-mcbsp.c

@@ -644,15 +644,23 @@ static int omap_mcbsp_dai_set_dai_sysclk(struct snd_soc_dai *cpu_dai,
 
 
 	case OMAP_MCBSP_CLKR_SRC_CLKR:
+		if (cpu_class_is_omap1())
+			break;
 		omap2_mcbsp1_mux_clkr_src(CLKR_SRC_CLKR);
 		break;
 	case OMAP_MCBSP_CLKR_SRC_CLKX:
+		if (cpu_class_is_omap1())
+			break;
 		omap2_mcbsp1_mux_clkr_src(CLKR_SRC_CLKX);
 		break;
 	case OMAP_MCBSP_FSR_SRC_FSR:
+		if (cpu_class_is_omap1())
+			break;
 		omap2_mcbsp1_mux_fsr_src(FSR_SRC_FSR);
 		break;
 	case OMAP_MCBSP_FSR_SRC_FSX:
+		if (cpu_class_is_omap1())
+			break;
 		omap2_mcbsp1_mux_fsr_src(FSR_SRC_FSX);
 		break;
 	default: