arm: socfpga: fpga: Add SoCFPGA FPGA programming interface

arm: socfpga: fpga: Add SoCFPGA FPGA programming interface

Add code necessary to program the FPGA part of SoCFPGA from U-Boot
with an RBF blob. This patch also integrates the code into the
FPGA driver framework in U-Boot so it can be used via the 'fpga'
command.

Signed-off-by: Pavel Machek <[email protected]>
Signed-off-by: Marek Vasut <[email protected]>
Cc: Chin Liang See <[email protected]>
Cc: Dinh Nguyen <[email protected]>
Cc: Albert Aribaud <[email protected]>
Cc: Tom Rini <[email protected]>
Cc: Wolfgang Denk <[email protected]>
Cc: Pavel Machek <[email protected]>
V2: Move the not-CPU specific stuff into drivers/fpga/ and base
    this on the cleaned up altera FPGA support.