MIPS: rename INFINEON_EBU_BOOTCFG to CONFIG_SYS_XWAY_EBU_BOOTFG

This define is a board-specific config option and should be
renamed to follow the U-Boot naming convention. Additionally,
add an explaining comment for this option.

Signed-off-by: Daniel Schwierzeck <daniel.schwierzeck@googlemail.com>
Acked-by: Thomas Langer <thomas.langer@lantiq.com>
Signed-off-by: Shinya Kuribayashi <skuribay@pobox.com>
diff --git a/include/configs/incaip.h b/include/configs/incaip.h
index 57eb2fa..0e5ad2b4 100644
--- a/include/configs/incaip.h
+++ b/include/configs/incaip.h
@@ -41,7 +41,7 @@
 #define CONFIG_CPU_CLOCK_RATE	150000000
 #endif
 
-#define INFINEON_EBU_BOOTCFG	0x40C4	/* CMULT = 8 */
+#define CONFIG_SYS_XWAY_EBU_BOOTCFG	0x40C4	/* CMULT = 8 */
 
 #define CONFIG_BOOTDELAY	5	/* autoboot after 5 seconds	*/