package/kodi: Remove dependency for BR2_TOOLCHAIN_GCC_AT_LEAST_4_7 from sub packages

Kodi itself already depends on BR2_TOOLCHAIN_GCC_AT_LEAST_4_7, there is
no need to duplicate this as reverse dependencies in sub options which
depend on Kodi.

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