u-boot-aspeed: use upstream u-boot.inc

Move u-boot-aspeed-sdk to use u-boot.inc from poki instead our own.  We
still need our own one for old u-boot-aspeed, so keep it as is.

Tested: Build image for AST2500-based machine with
u-boot-aspeed-sdk_2019.04, verified that it boots up and fw-utils
installed to the image properly.

Signed-off-by: Andrei Kartashev <a.kartashev@yadro.com>
Change-Id: Ia5fecdedc94e9550196420884a727e7d87b313d4
diff --git a/meta-aspeed/recipes-bsp/u-boot/u-boot-common-aspeed-sdk_2019.04.inc b/meta-aspeed/recipes-bsp/u-boot/u-boot-common-aspeed-sdk_2019.04.inc
index 02c5fcd..2aa4ad2 100644
--- a/meta-aspeed/recipes-bsp/u-boot/u-boot-common-aspeed-sdk_2019.04.inc
+++ b/meta-aspeed/recipes-bsp/u-boot/u-boot-common-aspeed-sdk_2019.04.inc
@@ -9,9 +9,13 @@
 # We use the revision in order to avoid having to fetch it from the
 # repo during parse
 SRCREV = "a570745a1a836e351bd4b1131f23a4fa5013d6dd"
-
 SRC_URI = "git://git@github.com/openbmc/u-boot.git;nobranch=1;protocol=https"
 
 S = "${WORKDIR}/git"
+B = "${WORKDIR}/build"
+do_configure[cleandirs] = "${B}"
+
+# We don't have 'u-boot-initial-env' target in our u-boot version
+UBOOT_INITIAL_ENV=""
 
 PV = "v2019.04+git${SRCPV}"