meta-amd: fix compilation errors with latest Yocto

Make the following changes to fix compilation errors:
- add honister to the LAYERSERIES_COMPAT variable,
- increase CONF_VERSION to 2,
- use new bitbake override syntax

Signed-off-by: Konstantin Aladyshev <aladyshev22@gmail.com>
Change-Id: I971f0f0f7110e0350994ced151ca429444885056
diff --git a/meta-amd/meta-ethanolx/conf/machine/ethanolx.conf b/meta-amd/meta-ethanolx/conf/machine/ethanolx.conf
index 7fb6e7e..2ac82ca 100644
--- a/meta-amd/meta-ethanolx/conf/machine/ethanolx.conf
+++ b/meta-amd/meta-ethanolx/conf/machine/ethanolx.conf
@@ -2,7 +2,7 @@
 KMACHINE = "aspeed"
 KERNEL_DEVICETREE = "${KMACHINE}-bmc-amd-${MACHINE}.dtb"
 
-UBOOT_MACHINE_ethanolx = "ast_g5_phy_config"
+UBOOT_MACHINE:ethanolx = "ast_g5_phy_config"
 
 require conf/machine/include/ast2500.inc
 require conf/machine/include/obmc-bsp-common.inc