This commit does two things:
1. First, it reorganizes the driver Kconfig files so that each is self contained. Before, a part of the driver configuration was in drivers/Kconfig and the rest was in in drivers/xyz/Konfig. Now, all of the driver configuration is consolitated in the latter.
2. Second, this commit correct numerous serious errors introduced in a previous reorganization of the driver Kconfig files. This was first noted by Nicholas Chin in PR270 for the case of the drivers/i2c/Kconfig but some examination indicates that the error was introduced into several other Kconfig files as well.
The nature of the introduced error was basically this:
- Nothing must intervene between the menuconfig selection and the following conditional configuration otpions.
- A previous PR erroneously introduced unconditional options between the menuconfig and the following confditional logic, thus corrupting the driver menus.
This error was easy to make because the driver Kconfig files were not well modularized. Making them fully self-contained should eliminate this kind of error in the future.
Feature pca9540bdp i2cmultiplexer
* Implement common i2c multiplexer abstraction to be reused by i2c multiplexer devices. Provide common interface with transfer and reset calls to set up virtual i2c busses.
* Remove i2cmux_lower_half.c and headers, will be implemented by each mux driver
* Implement PCA9540BDP I2C multiplexer lower half which uses the common i2c mux abstraction
* Remove application interface and implement common i2c functions
* Remove application interface from pca driver and implement common i2c functions directly in the pca driver
* Use i2cerr
Approved-by: Gregory Nutt <gnutt@nuttx.org>