serial: stm32: Fix bits defines name

Rename USART_ISR_FLAG_xxx bits to USART_ISR_xxx bits and
USART_ICR_OREF to USART_ICR_ORECF in order to match datasheets.
Sort defines by descendant order.

Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/serial/serial_stm32.h b/drivers/serial/serial_stm32.h
index 8a1a24f..c478e35 100644
--- a/drivers/serial/serial_stm32.h
+++ b/drivers/serial/serial_stm32.h
@@ -59,13 +59,13 @@
 
 #define USART_CR3_OVRDIS		BIT(12)
 
-#define USART_ISR_FLAG_ORE		BIT(3)
-#define USART_ISR_FLAG_RXNE		BIT(5)
-#define USART_ISR_FLAG_TXE		BIT(7)
+#define USART_ISR_TXE			BIT(7)
+#define USART_ISR_RXNE			BIT(5)
+#define USART_ISR_ORE			BIT(3)
 
 #define USART_BRR_F_MASK		GENMASK(7, 0)
 #define USART_BRR_M_SHIFT		4
 #define USART_BRR_M_MASK		GENMASK(15, 4)
 
-#define USART_ICR_OREF			BIT(3)
+#define USART_ICR_ORECF			BIT(3)
 #endif