Do not hardcode paths in eglfs-brcm test.

Let the specs decide about egl headers and egl lib
location.

Fixes yocto RaspberryPi build without proper
egl support.

Change-Id: I4c8d655673aa0b2043bc376486cfe436afb93e42
Reviewed-by: Laszlo Agocs <laszlo.agocs@theqtcompany.com>

config.tests/qpa/eglfs-brcm/eglfs-brcm.pro

@@ -2,8 +2,6 @@ SOURCES = eglfs-brcm.cpp
 
 CONFIG -= qt
 
-INCLUDEPATH += $$[QT_SYSROOT]/opt/vc/include \
-               $$[QT_SYSROOT]/opt/vc/include/interface/vcos/pthreads \
-               $$[QT_SYSROOT]/opt/vc/include/interface/vmcs_host/linux
+INCLUDEPATH += $$QMAKE_INCDIR_EGL
 
-LIBS += -L$$[QT_SYSROOT]/opt/vc/lib -lEGL -lGLESv2 -lbcm_host
+LIBS += -L$$QMAKE_LIBDIR_EGL -lEGL -lGLESv2 -lbcm_host