fpga: dfl: add FPGA Management Engine driver basic framework

The FPGA Management Engine (FME) provides power, thermal management,
performance counters, partial reconfiguration and other functions. For each
function, it is packaged into a private feature linked to the FME feature
device in the 'Device Feature List'. It's a platform device created by
DFL framework.

This patch adds the basic framework of FME platform driver. It defines
sub feature drivers to handle the different sub features, including init,
uinit and ioctl. It also registers the file operations for the device file.

Signed-off-by: Tim Whisonant <tim.whisonant@intel.com>
Signed-off-by: Enno Luebbers <enno.luebbers@intel.com>
Signed-off-by: Shiva Rao <shiva.rao@intel.com>
Signed-off-by: Christopher Rauer <christopher.rauer@intel.com>
Signed-off-by: Kang Luwei <luwei.kang@intel.com>
Signed-off-by: Xiao Guangrong <guangrong.xiao@linux.intel.com>
Signed-off-by: Wu Hao <hao.wu@intel.com>
Acked-by: Alan Tull <atull@kernel.org>
Acked-by: Moritz Fischer <mdf@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>