package/libcec: bump to version 3.0.1

- reflect upstream changes of the build system by switching from
  an autotools-package to cmake-package

[Thomas:
  - remove the gcc 4.5 dependency. While we do need a dependency on
    the gcc version, the proposed implementation was not correct as it
    wasn't handling external toolchains.
  - add a patch to fix a problem caused by libcec build system trying
    to use 'git' to get a version number, which does not work when the
    version control system information is not available, as is the
    case in Buildroot.]

Signed-off-by: Bernd Kuhls <bernd.kuhls@t-online.de>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>