mips: malta: build u-boot-swap.bin

The Qemu Malta machine expects the firmware in Big-Endian byte order.
Therefore the Little-Endian variants of the Malta board needs to
be byte swapped.

Signed-off-by: Daniel Schwierzeck <daniel.schwierzeck@gmail.com>

configs/malta64el_defconfig

@@ -3,6 +3,7 @@ CONFIG_SYS_TEXT_BASE=0xFFFFFFFFBE000000
 CONFIG_ENV_SIZE=0x20000
 CONFIG_ENV_SECT_SIZE=0x20000
 CONFIG_TARGET_MALTA=y
+CONFIG_BUILD_TARGET="u-boot-swap.bin"
 CONFIG_SYS_LITTLE_ENDIAN=y
 CONFIG_CPU_MIPS64_R2=y
 CONFIG_MISC_INIT_R=y

configs/maltael_defconfig

@@ -3,6 +3,7 @@ CONFIG_SYS_TEXT_BASE=0xBE000000
 CONFIG_ENV_SIZE=0x20000
 CONFIG_ENV_SECT_SIZE=0x20000
 CONFIG_TARGET_MALTA=y
+CONFIG_BUILD_TARGET="u-boot-swap.bin"
 CONFIG_SYS_LITTLE_ENDIAN=y
 CONFIG_MISC_INIT_R=y
 CONFIG_BOARD_EARLY_INIT_F=y