[yocto] ia32-base.inc: Drop glibc --with-tls option, its now the only option for glibc

[Richard Purdie]

This option is unused by (e)glibc since 2011 and is the default. It has been
shown to interact badly with the configure option in atom-pc from meta-yocto 
causing a rebuild of the whole system despite the only change being an 
assignment with += vs =. The easiest fix is simply to drop it.
    
Signed-off-by: Richard Purdie <richard.purdie at linuxfoundation.org>

diff --git a/conf/machine/include/ia32-base.inc b/conf/machine/include/ia32-base.inc
index 99ac352..17ff714 100644
--- a/conf/machine/include/ia32-base.inc
+++ b/conf/machine/include/ia32-base.inc
@@ -21,7 +21,6 @@ SERIAL_CONSOLE ?= "115200 ttyS0"
 # glibc-related variables
 #
 GLIBC_ADDONS ?= "nptl"
-GLIBC_EXTRA_OECONF += "--with-tls"
 
 #
 # kernel-related variables