sparc: leon3: Updated serial driver to use CONFIG_CONS_INDEX

Updated the LEON3 serial driver to make use of the CONFIG_CONS_INDEX
option to select which serial port the console will use.

Signed-off-by: Francois Retief <fgretief@spaceteq.co.za>
diff --git a/arch/sparc/cpu/leon3/serial.c b/arch/sparc/cpu/leon3/serial.c
index 5348a78..bc6e7a1 100644
--- a/arch/sparc/cpu/leon3/serial.c
+++ b/arch/sparc/cpu/leon3/serial.c
@@ -17,8 +17,13 @@
 
 /* Select which UART that will become u-boot console */
 #ifndef CONFIG_SYS_GRLIB_APBUART_INDEX
+/* Try to use CONFIG_CONS_INDEX, if available, it is numbered from 1 */
+#ifdef CONFIG_CONS_INDEX
+#define CONFIG_SYS_GRLIB_APBUART_INDEX (CONFIG_CONS_INDEX - 1)
+#else
 #define CONFIG_SYS_GRLIB_APBUART_INDEX 0
 #endif
+#endif
 
 static unsigned apbuart_calc_scaler(unsigned apbuart_freq, unsigned baud)
 {