omap3: Drop CONFIG_OMAP3_EVM, switch to CONFIG_TARGET_OMAP3_EVM when needed

We make use of CONFIG_OMAP3_EVM today to know when to do a specific
tweak in MUSB.  This can be tested on via CONFIG_TARGET_OMAP3_EVM
instead, so switch there so we can drop the now unused symbol
CONFIG_OMAP3_EVM.  In investigating what to do about the symbol usage we
see that the cairo board defines the same function, but never called it
(as it does not define CONFIG_OMAP3_EVM) and was just returning anyhow,
so drop that function from that board.

Cc: "Albert ARIBAUD (3ADEV)" <albert.aribaud@3adev.fr>
Cc: Marek Vasut <marex@denx.de>
Signed-off-by: Tom Rini <trini@konsulko.com>

drivers/usb/musb/omap3.c

@@ -118,7 +118,7 @@ int musb_platform_init(void)
 		stdby &= ~OMAP3_OTG_FORCESTDBY_STANDBY;
 		writel(stdby, &otg->forcestdby);
 
-#ifdef CONFIG_OMAP3_EVM
+#ifdef CONFIG_TARGET_OMAP3_EVM
 		musb_cfg.extvbus = omap3_evm_need_extvbus();
 #endif
 

drivers/usb/musb/omap3.h

@@ -32,7 +32,7 @@
 
 int musb_platform_init(void);
 
-#ifdef CONFIG_OMAP3_EVM
+#ifdef CONFIG_TARGET_OMAP3_EVM
 extern u8 omap3_evm_need_extvbus(void);
 #endif