firmware: altera: Make nSTAT GPIO optional ...

By taking parts of the programming handshaking protocol on faith it is
possible to make due with only two GPIO for programming Altera
FPGAs. This is not a very advisable practice, but sometime unavoidable
in GPIO constrained designs.

Signed-off-by: Andrey Smirnov <andrew.smirnov@gmail.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

firmware: altera-serial: fix printf message ...

Fixes:
.../altera_serial.c:118:2: warning: too many arguments for format

Also sz is of type size_t, so use proper format specifier.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

firmware: altera-serial: don't try to check void return value ...

Fixes:
.../altera_serial.c:84:6: error: void value not ignored as it ought to be

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>

Firmware: provide a handler to program Altera FPGAs ...

This handler uses a regular SPI master and a few GPIOs to program an
Altera FPGA in serial mode.

Signed-off-by: Juergen Beisert <jbe@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>
Signed-off-by: Steffen Trumtrar <s.trumtrar@pengutronix.de>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>