Revert "usb: phy: dual-role: update sysfs attrs when changed"

This reverts commit d1263829.

The previous approach of dynamically updating the writeable
permission bits of the power/data_role attributes only works
if the userspace application has root permission since the
call to sysfs_update_group() removes and re-adds the files. If
they had previously been chown/chgrp'ed, the ownership would be
reset. On the other hand, if there was a ueventd rule to
dynamically update the ownership, then the mode would always
be overridden with the static umask given in the ueventd rule,
contradicting the driver's determination of writeability.

Hence, the more comprehensive fix should be done in userspace
to not rely solely on writeability. Still, this change needs
to be reverted since it can still cause a race between ueventd
and the userspace service trying to check writability.

Change-Id: Ic667a97f2bae41e5a86ee45565518b06db959b36
Signed-off-by: Jack Pham <jackp@codeaurora.org>