meta-intel-openbmc: prep for new override syntax

Ran `scripts/contrib/convert-overrides.py` from upstream Yocto and
fixed up a few by hand that were missed.

Tested: Built s2600wf.

Signed-off-by: Jae Hyun Yoo <jae.hyun.yoo@linux.intel.com>
Change-Id: I983385c8cdd4e2727c5c1a3d56952d6ac7fd89cc
diff --git a/meta-intel-openbmc/meta-common/recipes-x86/chassis/x86-power-control_%.bbappend b/meta-intel-openbmc/meta-common/recipes-x86/chassis/x86-power-control_%.bbappend
index 5d47989..b27f908 100644
--- a/meta-intel-openbmc/meta-common/recipes-x86/chassis/x86-power-control_%.bbappend
+++ b/meta-intel-openbmc/meta-common/recipes-x86/chassis/x86-power-control_%.bbappend
@@ -1,2 +1,2 @@
 # Use PLT_RST to detect warm resets
-EXTRA_OECMAKE_intel += "-DUSE_PLT_RST=ON"
+EXTRA_OECMAKE:intel += "-DUSE_PLT_RST=ON"