x86: Don't generate .note.gnu.build-id section

This patch adds "--build-id=none" to default LDFLAGS so
.note.gnu.build-id section is not generated. This section
contains unique identification for the built files what is
not important to us (at least at this moment).

This change simplifies all linker scripts for SoCs based on x86
(at this moment we only have Quark X1000) since we don't have to
care about it anymore.

cpu/x86/Makefile.x86_common

@@ -12,7 +12,7 @@ STRIP    = strip
 CFLAGSNO = -Wall -g -I/usr/local/include
 CFLAGS  += $(CFLAGSNO)
 ifeq ($(HOST_OS),Linux)
-  LDFLAGS  = -Wl,-Map=contiki-$(TARGET).map,-export-dynamic
+  LDFLAGS  = -Wl,-Map=contiki-$(TARGET).map,-export-dynamic,--build-id=none
 else
   LDFLAGS  = -Wl
 endif

cpu/x86/quarkX1000.ld

@@ -60,10 +60,4 @@ SECTIONS {
         *(COMMON)
         *(.bss)
     }
-
-    /* Put this here so it doesn't sit above the multiboot section. */
-    .note.gnu.build-id :
-    {
-        *(.note.gnu.build-id)
-    }
 }