ti_omap3_common: Add CONFIG_SYS_NS16550_COMx entries

Several boards do not use the default UART3, so they do a check
for ifdef CONFIG_SPL_BUILD and enable the pointer for
CONFIG_SYS_NS16550_COMx to point to OMAP34XX_UARTx.

Let's consoldate this all into one place, and remove them from the
individual boards.

Signed-off-by: Adam Ford <aford173@gmail.com>
diff --git a/include/configs/ti_omap3_common.h b/include/configs/ti_omap3_common.h
index 7cd4272c..6d16fc7 100644
--- a/include/configs/ti_omap3_common.h
+++ b/include/configs/ti_omap3_common.h
@@ -38,6 +38,8 @@
 
 /* Select serial console configuration */
 #ifdef CONFIG_SPL_BUILD
+#define CONFIG_SYS_NS16550_COM1		OMAP34XX_UART1
+#define CONFIG_SYS_NS16550_COM2		OMAP34XX_UART2
 #define CONFIG_SYS_NS16550_COM3		OMAP34XX_UART3
 #define CONFIG_SERIAL3			3
 #endif