i2c: fsl_i2c: Migrate to Kconfig

- As there are no boards that use different values for speed / slave on
  different buses, use a single option.
- Switch to using the common SYS_I2C_SPEED / SYS_I2C_SLAVE options.
- Introduce _HAS_ options for additional buses as only the first one is
  common to all users.
- Convert all remaining symbols to Kconfig.

Signed-off-by: Tom Rini <trini@konsulko.com>
141 files changed