Revert "of/platform: Move platform devices under /sys/devices/platform"

This reverts commit 43c0767e17ac ("of/platform: Move platform
devices under /sys/devices/platform"). Userspace code that
expects to find devices under a fixed /sys/devices/... path are
affected by moving platform devices under /sys/devices/platform.

Change-Id: I6a108c46c1b2e3985797bb86a3ed84a29ab286a8
Signed-off-by: Kaushal Kumar <kaushalk@codeaurora.org>