MIPS: start.S: make boot config at offset 0x10 configurable

Some MIPS systems store some board-specific boot configuration
in the U-Boot binary at offset 0x10. This is used by Malta boards
and by Lantiq/Intel SoC's when booting from parallel NOR flash.

Convert the hard-coded values to Kconfig options to remove such
board-specific stuff out of the generic start.S code. This also
deprecates the config option CONFIG_SYS_XWAY_EBU_BOOTCFG.

Signed-off-by: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>
diff --git a/arch/mips/Kconfig b/arch/mips/Kconfig
index 6e5e0ff..f71597f 100644
--- a/arch/mips/Kconfig
+++ b/arch/mips/Kconfig
@@ -28,6 +28,7 @@
 	select DM_SERIAL
 	select DYNAMIC_IO_PORT_BASE
 	select MIPS_CM
+	select MIPS_INSERT_BOOT_CONFIG
 	select MIPS_L1_CACHE_SHIFT_6
 	select MIPS_L2_CACHE
 	select OF_CONTROL
@@ -390,6 +391,28 @@
 	  wish U-Boot to configure it or make use of it to retrieve system
 	  information such as cache configuration.
 
+config MIPS_INSERT_BOOT_CONFIG
+	bool
+	default n
+	help
+	  Enable this to insert some board-specific boot configuration in
+	  the U-Boot binary at offset 0x10.
+
+config MIPS_BOOT_CONFIG_WORD0
+	hex
+	depends on MIPS_INSERT_BOOT_CONFIG
+	default 0x420 if TARGET_MALTA
+	default 0x0
+	help
+	  Value which is inserted as boot config word 0.
+
+config MIPS_BOOT_CONFIG_WORD1
+	hex
+	depends on MIPS_INSERT_BOOT_CONFIG
+	default 0x0
+	help
+	  Value which is inserted as boot config word 1.
+
 endif
 
 endmenu