eglibc/machine-sdk: Drop SDK_GLIBC_ADDONS

We no longer change GLIBC_ADDONS per target so we no longer need to special
case the SDK settings for it either.

(From OE-Core rev: 3fb0e792600b5adb58bc5fca90d8605c1c76280f)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

meta/conf/machine-sdk/i586.conf

@@ -1,4 +1,3 @@
 SDK_ARCH = "i586"
 SDK_CC_ARCH = "-march=i586"
 
-SDK_GLIBC_ADDONS = "nptl"

meta/conf/machine-sdk/i686.conf

@@ -1,4 +1,2 @@
 SDK_ARCH = "i686"
 SDK_CC_ARCH = "-march=i686"
-
-SDK_GLIBC_ADDONS = "nptl"

meta/conf/machine-sdk/x86_64.conf

@@ -1,3 +1 @@
 SDK_ARCH = "x86_64"
-
-SDK_GLIBC_ADDONS = "nptl"

meta/recipes-core/eglibc/eglibc.inc

@@ -78,5 +78,3 @@ do_configure_append() {
 }
 
 GLIBC_ADDONS ?= "ports,nptl,libidn"
-SDK_GLIBC_ADDONS ?= "ports,nptl,libidn"
-GLIBC_ADDONS_class-nativesdk = "${SDK_GLIBC_ADDONS}"