fpga: altera: Add StratixV support

This patch adds support for programming of the StratixV FPGAs. Programming
is done in this case (board theadorable) via SPI. The board may provide
board specific code for bitstream programming.

This StratixV support will be used by the theadorable board.

Signed-off-by: Stefan Roese <sr@denx.de>
Cc: Tom Rini <trini@konsulko.com>
Signed-off-by: Stefan Roese <sr@denx.de>