Mark lr::write as deprecated

Author: jannic

src/register/lr.rs

@@ -11,7 +11,11 @@ pub fn read() -> u32 {
 /// Writes `bits` to the CPU register
 ///
 /// **NOTE** This function is available if `cortex-m` is built with the `"inline-asm"` feature.
+///
+/// # Safety
+/// This function can't be used soundly.
 #[inline]
+#[deprecated = "This function can't be used soundly."]
 pub unsafe fn write(bits: u32) {
     call_asm!(__lr_w(bits: u32));
 }