qt5: bump latest version to 5.9.3

qt5: bump latest version to 5.9.3

qt5connectivity:
 - moved 0001-Example-heartrate-server-needs-only-core-and-bluetoo.patch
   to 5.9.3

qt5declarative:
 - removed 0001-Fix-no-opengl-builds.patch to 5.9.3 (upstream committed,
   see [1])

qt5webengine:
 - keep 0002-Load-libEGL-and-libGLES2-symbols-implicitly.patch
   (upstream committed, see [2], but reverted afterwards, see [3])

[1] https://code.qt.io/cgit/qt/qtdeclarative.git/commit/?id=fa52bb665d6beb77a951c14c8edcba3541850afc
[2] https://code.qt.io/cgit/qt/qtwebengine.git/commit/?id=d4c621f6a6b87f2a86069fa393b9f7c4f9e7b9ad
[3] https://code.qt.io/cgit/qt/qtwebengine.git/commit/?id=c11c2c8981e647c1eb2c6753ce77d436b92fff87

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>