* Added var $platform which is similar to $i2c and accommodates the conversion

* Added var $platform which is similar to $i2c and accommodates the conversion
    of many devices from /sys/bus/i2c/devices to /sys/bus/platform/devices.
* Removed config item post_21_kernel since it forced all i2c device lookups
    to go to /sys/bus/platform/devices and some people may need a mix of both
    i2c and platform devices.

git-svn-id: https://conky.svn.sourceforge.net/svnroot/conky/trunk/conky1@917 7f574dfc-610e-0410-a909-a81674777703