update all struct headers to be more "standardized":
- bit fields are properly wrapped with struct
- bitwidth sum should be 32 within same struct, so that it's correctly padded with reserved bits
- bit field should be uint32_t
- typedef volatile struct xxx{} yyy;: xxx must exists. refer: https://github.com/espressif/esp-idf/pull/3199
added helper macros to force peripheral registers being accessed in 32 bitwidth
added a check script into ci
The user can now request the chip select to remain active after the current
transfer. In order to do so, he MUST acquire the bus first with `spi_device_acquire_bus()`
function, else, an error is returned.
Furthermore, RX_EOF_EN should only be set when SPI Slave is configured
for segment transfer mode and the "ms_data_bitlen" field is configured
to control the "IN_SUC_EOF" interrupt. Since "ms_data_bitlen" is not
set anymore for S2, C3 and S3, "RX_EOF_EN" should be cleared.
