This commit makes the following changes:
Add SPI Engine for serial mode
Add SER_PAR_N build parameter, set default 1 for serial
Fix irq consistency in ad7616_bd.tcl
Fix regmap and offload names
Fix system_top.v GPIOs
Running 'make' will build the default project directly in the project folder (like it did before)
Running 'make RX_LANE_RATE=15 TX_LANE_RATE=15' will build the project inside the 'RXRATE15_TXRATE15' subdirectory.
Running 'make CFG=cfg/test_config.txt" will use the variables found inside the configuration file and build the project inside the 'test_config' subdirectory.
Running 'make clean' will clean the default project only.
Running 'make CFG=cfg/test_config.txt clean' will clean the 'testconfig' build.
Running 'make clean-all' will delete all the built configurations and libraries.
Note that the 'JESD' and 'LANE' words from the parameter names are stripped.
Signed-off-by: Bogdan Luncan <bogdan.luncan@analog.com>