Update SPI impls for STM32F334

Based on the datasheet, the following pins and peripherals are
supported:
- SPI1:
  - SCK:  PA5<AF5>, PB3<AF5>
  - MISO: PA6<AF5>, PB4<AF5>
  - MOSI: PA7<AF5>, PB5<AF5>

Author: danielgallagher0

src/spi.rs

@@ -51,6 +51,7 @@ use crate::gpio::gpiob::{PB14, PB15, PB5};
     feature = "stm32f303",
     feature = "stm32f318",
     feature = "stm32f328",
+    feature = "stm32f334",
     feature = "stm32f358",
     feature = "stm32f373",
     feature = "stm32f378",
@@ -161,6 +162,7 @@ unsafe impl SckPin<SPI1> for PA12<AF6> {}
     feature = "stm32f302xe",
     feature = "stm32f303",
     feature = "stm32f328",
+    feature = "stm32f334",
     feature = "stm32f358",
     feature = "stm32f373",
     feature = "stm32f378",
@@ -269,6 +271,7 @@ unsafe impl MisoPin<SPI1> for PA13<AF6> {}
     feature = "stm32f302xe",
     feature = "stm32f303",
     feature = "stm32f328",
+    feature = "stm32f334",
     feature = "stm32f358",
     feature = "stm32f373",
     feature = "stm32f378",