u-boot-sdk: Remove u-boot.bin make target

The recipe was first created with the make target set to
u-boot.bin because there were some compilation errors.

These errors are not seeing anymore. By removing the u-boot.bin
target and allowing it to be the default (all), other targets
like u-boot-spl.bin can be automatically built based on the
defconfig.

Change-Id: Ifb5ed3cc04c187725b2d877c2be5e81f422df4e6
Signed-off-by: Adriana Kobylak <anoo@us.ibm.com>
diff --git a/recipes-bsp/u-boot/u-boot-aspeed-sdk_2019.04.bb b/recipes-bsp/u-boot/u-boot-aspeed-sdk_2019.04.bb
index 4910685..78c352f 100644
--- a/recipes-bsp/u-boot/u-boot-aspeed-sdk_2019.04.bb
+++ b/recipes-bsp/u-boot/u-boot-aspeed-sdk_2019.04.bb
@@ -1,6 +1,6 @@
 require u-boot-common-aspeed-sdk_${PV}.inc
 
-UBOOT_MAKE_TARGET ?= "u-boot.${UBOOT_SUFFIX} DEVICE_TREE=${UBOOT_DEVICETREE}"
+UBOOT_MAKE_TARGET ?= "DEVICE_TREE=${UBOOT_DEVICETREE}"
 
 require recipes-bsp/u-boot/u-boot.inc