[package_info_linux] fix platform interface dependency version

[jpnurmi]

Because every version of package_info_plus from path depends on package_info_plus_linux ^0.1.0 which depends on package_info_plus_platform_interface ^0.1.0, every version of package_info_plus from path requires package_info_plus_platform_interface ^0.1.0.
So, because package_info_example depends on package_info_plus from path which depends on package_info_plus_platform_interface ^0.3.0, version solving failed.