raw/ifpga/base: add Intel FPGA OPAE share code

raw/ifpga/base: add Intel FPGA OPAE share code

This patch adds Intel FPGA Open Programmable Acceleration
Engine (OPAE)[1] base driver code, in order to support Intel
FPGA devices under DPDK. The base code currently supports
Intel FPGA solutions including integrated solution (Intel(R)
Xeon(R) CPU with FPGAs) and discrete solution (Intel(R)
Programmable Acceleration Card with Intel(R) Arria(R) 10 FPGA)
and it could be extended to support more FPGA devices in the
future. Please refer to [1][2] for more introduction on OPAE
and Intel FPGAs.

[1] https://01.org/OPAE
[2] https://www.altera.com/solutions/acceleration-hub/overview.html

Signed-off-by: Tianfei Zhang <tianfei.zhang@intel.com>
Signed-off-by: Hao Wu <hao.wu@intel.com>
Signed-off-by: Yilun Xu <yilun.xu@intel.com>
Reviewed-by: Qi Zhang <qi.z.zhang@intel.com>