[meta-qt5]remove -reduce-relocations on arm platform

[Neuer User <auslands-kv@gmx.de>]

On arm platform the compiler does not implement "-reduce-relocations",
see here: https://bugreports.qt-project.org/browse/QTBUG-36129

The meta-qt5 layer, however, uses this option, so configure will fail
for qtbase.

This patch fixes the problem for me, but it should better test on the
platform and only apply it, when it is an arm platform:

diff --git a/recipes-qt/qt5/qtbase.inc b/recipes-qt/qt5/qtbase.inc
index 89736be..f23236a 100644
--- a/recipes-qt/qt5/qtbase.inc
+++ b/recipes-qt/qt5/qtbase.inc
@@ -126,7 +126,6 @@ PACKAGECONFIG[nis] = "-nis,-no-nis"
 PACKAGECONFIG[widgets] = "-widgets,-no-widgets"

 QT_CONFIG_FLAGS += " \
-    -reduce-relocations \
     -shared \
     -silent \
     -no-pch \