plugins: Add more cleanup when closing the plugins

Signed-off-by: Paul Cercueil <paul.cercueil@analog.com>
plugins: Add save_profile / load_profile callbacks

Signed-off-by: Paul Cercueil <paul.cercueil@analog.com>
libini2.c: Fix detection of tokens

Signed-off-by: Paul Cercueil <paul.cercueil@analog.com>
libini2.c: Added function foreach_in_ini

This function calls a callback function for each token found in the INI.
If the callback returns an error, all entries in the INI are skipped
until a new section is found.

Signed-off-by: Paul Cercueil <paul.cercueil@analog.com>
Osc: Changes to use the new INI functions

Signed-off-by: Paul Cercueil <paul.cercueil@analog.com>
Remove all references to the old INI code entirely

Signed-off-by: Paul Cercueil <paul.cercueil@analog.com>