stm32/rcc: remove builders on Config.

This makes API consistent with other Config structs in Embassy, where
the convention is to not use builders.

embassy-stm32/src/rcc/l1/mod.rs

@@ -118,10 +118,10 @@ impl Into<u8> for MSIRange {
 
 /// Clocks configutation
 pub struct Config {
-    mux: ClockSrc,
-    ahb_pre: AHBPrescaler,
-    apb1_pre: APBPrescaler,
-    apb2_pre: APBPrescaler,
+    pub mux: ClockSrc,
+    pub ahb_pre: AHBPrescaler,
+    pub apb1_pre: APBPrescaler,
+    pub apb2_pre: APBPrescaler,
 }
 
 impl Default for Config {
@@ -136,32 +136,6 @@ impl Default for Config {
     }
 }
 
-impl Config {
-    #[inline]
-    pub fn clock_src(mut self, mux: ClockSrc) -> Self {
-        self.mux = mux;
-        self
-    }
-
-    #[inline]
-    pub fn ahb_pre(mut self, pre: AHBPrescaler) -> Self {
-        self.ahb_pre = pre;
-        self
-    }
-
-    #[inline]
-    pub fn apb1_pre(mut self, pre: APBPrescaler) -> Self {
-        self.apb1_pre = pre;
-        self
-    }
-
-    #[inline]
-    pub fn apb2_pre(mut self, pre: APBPrescaler) -> Self {
-        self.apb2_pre = pre;
-        self
-    }
-}
-
 /// RCC peripheral
 pub struct Rcc<'d> {
     _rb: peripherals::RCC,