clk: clk_stm32f: Add DSI clock support

DSI clock is available on STM32F769-disco and
STM32F469-disco board.

Signed-off-by: Yannick Fertre <yannick.fertre@st.com>
Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
diff --git a/drivers/clk/clk_stm32f.c b/drivers/clk/clk_stm32f.c
index a683911..d8eab1a 100644
--- a/drivers/clk/clk_stm32f.c
+++ b/drivers/clk/clk_stm32f.c
@@ -432,7 +432,7 @@
 		return (sysclk >> stm32_get_apb_shift(regs, APB1));
 
 	/* APB2 CLOCK */
-	case STM32F7_APB2_CLOCK(TIM1) ... STM32F7_APB2_CLOCK(LTDC):
+	case STM32F7_APB2_CLOCK(TIM1) ... STM32F7_APB2_CLOCK(DSI):
 		switch (clk->id) {
 		/*
 		 * particular case for SDMMC1 and SDMMC2 :