[stm32] Fix Rcc::disable() erroneously disabling unrelated clocks

Due to missing curly braces certain statements are not guarded by an if
condition and will always be executed. This causes some ethernet clocks
to always be disabled regardless of specified parameters.

src/modm/platform/clock/stm32/rcc_impl.hpp.in

@@ -141,11 +141,12 @@ Rcc::disable()
 
 	__DSB();
 	%% for peripheral, (st_per, bus) in rcc_enable.items() | sort
-	if constexpr (peripheral == Peripheral::{{ peripheral }})
+	if constexpr (peripheral == Peripheral::{{ peripheral }}) {
 		RCC->{{bus}} &= ~RCC_{{bus}}_{{st_per}}EN;{% if peripheral == "Eth" %} __DSB();
 		RCC->{{bus}} &= ~RCC_{{bus}}_{{st_per}}RXEN; __DSB();
 		RCC->{{bus}} &= ~RCC_{{bus}}_{{st_per}}TXEN;{% elif peripheral == "Usbotghs" %} __DSB();
 		RCC->{{bus}} &= ~RCC_{{bus}}_{{st_per}}ULPIEN;{% endif %}
+	}
 	%% endfor
 	__DSB();
 }