ARM: OMAP: Fix errors and warnings when building for one board

When customizing omap2plus_defconfig to build for only
one board (omap3evm), I came across these warnings and
errors (filenames truncated):

arch/arm/mach-omap2/board-generic.c:76:20: warning: 'omap4_init' defined but not used
arch/arm/mach-omap2/built-in.o: In function `omap2420_init_early':
arch/arm/mach-omap2/io.c:364: undefined reference to `omap2_set_globals_242x'
arch/arm/mach-omap2/io.c:366: undefined reference to `omap2xxx_voltagedomains_init'
arch/arm/mach-omap2/io.c:367: undefined reference to `omap242x_powerdomains_init'
arch/arm/mach-omap2/io.c:368: undefined reference to `omap242x_clockdomains_init'
arch/arm/mach-omap2/io.c:369: undefined reference to `omap2420_hwmod_init'
arch/arm/mach-omap2/built-in.o: In function `omap2430_init_early':
arch/arm/mach-omap2/io.c:376: undefined reference to `omap2_set_globals_243x'
arch/arm/mach-omap2/io.c:378: undefined reference to `omap2xxx_voltagedomains_init'
arch/arm/mach-omap2/io.c:379: undefined reference to `omap243x_powerdomains_init'
arch/arm/mach-omap2/io.c:380: undefined reference to `omap243x_clockdomains_init'
arch/arm/mach-omap2/io.c:381: undefined reference to `omap2430_hwmod_init'
arch/arm/mach-omap2/built-in.o: In function `omap4430_init_early':
arch/arm/mach-omap2/io.c:436: undefined reference to `omap2_set_globals_443x'
arch/arm/mach-omap2/io.c:438: undefined reference to `omap44xx_voltagedomains_init'
arch/arm/mach-omap2/io.c:439: undefined reference to `omap44xx_powerdomains_init'
arch/arm/mach-omap2/io.c:440: undefined reference to `omap44xx_clockdomains_init'
arch/arm/mach-omap2/io.c:441: undefined reference to `omap44xx_hwmod_init'

This patch fixes them.

Signed-off-by: Sanjeev Premi <premi@ti.com>
Acked-by: Thomas Weber <weber@corscience.de>
[tony@atomide.com: updated to fix warnings for board-generic.c]
Signed-off-by: Tony Lindgren <tony@atomide.com>
diff --git a/arch/arm/mach-omap2/io.c b/arch/arm/mach-omap2/io.c
index a5d8dce..25d20ce 100644
--- a/arch/arm/mach-omap2/io.c
+++ b/arch/arm/mach-omap2/io.c
@@ -359,6 +359,7 @@
 	omap_pm_if_early_init();
 }
 
+#ifdef CONFIG_ARCH_OMAP2
 void __init omap2420_init_early(void)
 {
 	omap2_set_globals_242x();
@@ -382,11 +383,13 @@
 	omap_hwmod_init_postsetup();
 	omap2430_clk_init();
 }
+#endif
 
 /*
  * Currently only board-omap3beagle.c should call this because of the
  * same machine_id for 34xx and 36xx beagle.. Will get fixed with DT.
  */
+#ifdef CONFIG_ARCH_OMAP3
 void __init omap3_init_early(void)
 {
 	omap2_set_globals_3xxx();
@@ -430,7 +433,9 @@
 	omap_hwmod_init_postsetup();
 	omap3xxx_clk_init();
 }
+#endif
 
+#ifdef CONFIG_ARCH_OMAP4
 void __init omap4430_init_early(void)
 {
 	omap2_set_globals_443x();
@@ -442,6 +447,7 @@
 	omap_hwmod_init_postsetup();
 	omap4xxx_clk_init();
 }
+#endif
 
 void __init omap_sdrc_init(struct omap_sdrc_params *sdrc_cs0,
 				      struct omap_sdrc_params *sdrc_cs1)