i2c: stm32f7: add description of atomic in struct stm32f7_i2c_dev

Add missing description of the atomic boolean in struct stm32f7_i2c_dev.

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