i2c: stm32f7: remove noisy and imprecise log messages

The log messages talk about 'bus recovery' while it is not a bus
recovery with 9 pulses but merely a controller reset. Controller resets
are not worth log messages. The 'bus busy' message should be emitted by
upper layers, a busy bus may be expected in some cases.

Signed-off-by: Wolfram Sang <wsa@kernel.org>
Reviewed-by: Alain Volmat <alain.volmat@foss.st.com>