gpu-amd-bin-mx51: new package

Freescale libraries, headers and executables for the AMD GPU on the
i.MX51, containing OpenGL/ES, OpenVG and EGL support.

Tested using:
    mx5loco_defconfig:
    BR2_TOOLCHAIN_EXTERNAL=y
    BR2_PACKAGE_QT5=y
    BR2_PACKAGE_QT5BASE_LICENSE_APPROVED=y
    BR2_PACKAGE_QT5BASE_EXAMPLES=y
    BR2_PACKAGE_QT5BASE_OPENGL_LIB=y
    BR2_PACKAGE_QT5BASE_EGLFS=y
    BR2_PACKAGE_QT5BASE_DEFAULT_QPA="eglfs"
    BR2_PACKAGE_QT5BASE_GIF=y
    BR2_PACKAGE_QT5BASE_JPEG=y
    BR2_PACKAGE_QT5BASE_PNG=y
    BR2_PACKAGE_QT5QUICKCONTROLS=y
    BR2_PACKAGE_FREESCALE_IMX=y
    BR2_PACKAGE_FREESCALE_IMX_PLATFORM_IMX53=y
    BR2_PACKAGE_GPU_AMD_BIN_MX51=y

[Thomas:
 - Order Config.in packages alphabetically
 - Minor formatting cleanup in Config.in file.]

Signed-off-by: Jérôme Pouiller <jezz@sysmic.org>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>