drivers: watchdog: stm32 iwdg starts with wdt_setup()

 the watchdog is enabled by the wdt_setup()
coming after the wdt_install_timeout.
Due to PR #44972, the code did not follow that.
This PR fixes the correct other in the sequence.

Signed-off-by: Francois Ramu <francois.ramu@st.com>
1 file changed