qtwebkit: fix textrel QA warnings when building qtwebkit for x86

qtwebkit: fix textrel QA warnings when building qtwebkit for x86

WARNING: QA Issue: ELF binary '/home/andre/rdk/rdk-master/build-vbox32/tmp/work/core2-32-rdk-linux/qtwebkit/5.4.0-r0/packages-split/qtwebkit/usr/lib/libQt5WebKit.so.5.4.0' has relocations in .text [textrel]

Patch from upstream webkit:

  https://bugs.webkit.org/show_bug.cgi?id=70610

Minor refresh required to apply cleanly to the older webkit sources used
by qtwebkit. Specifically, the patch needed to be modified to account
for PLATFORM(MAC) -> OS(DARWIN) renaming in recent webkit which is not
part of qtwebkit yet ( https://bugs.webkit.org/show_bug.cgi?id=99683 ).

(From meta-qt5 rev: a137e6e8b45f11c77f6615cfa6ff50d025669b11)

Signed-off-by: Andre McCurdy <armccurdy@gmail.com>
Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@osg.samsung.com>