meta-facebook: minerva: use common uboot dts

Revise the uboot path to ast2600-facebook.

Change-Id: I4415dc6f3c06ad6b7b4b99e996ebecbe4efe5c8d
Signed-off-by: Yang Chen <yang.chen@quantatw.com>
diff --git a/meta-facebook/meta-minerva/conf/machine/minerva.conf b/meta-facebook/meta-minerva/conf/machine/minerva.conf
index 7b2ee8a..742dfdd 100644
--- a/meta-facebook/meta-minerva/conf/machine/minerva.conf
+++ b/meta-facebook/meta-minerva/conf/machine/minerva.conf
@@ -2,7 +2,7 @@
 KERNEL_DEVICETREE = "aspeed/${KMACHINE}-bmc-facebook-${MACHINE}.dtb"
 
 UBOOT_MACHINE = "ast2600_openbmc_spl_defconfig"
-UBOOT_DEVICETREE = "ast2600-bletchley"
+UBOOT_DEVICETREE = "ast2600-facebook"
 SPL_BINARY = "spl/u-boot-spl.bin"
 SOCSEC_SIGN_ENABLE = "0"