stm32f7: clk: remove usart1 clock enable from board init

Before clock driver availability it was required to enable usart1 clock
for serial init but now with clock driver is taking care of usart1 clock.

Signed-off-by: Vikas Manocha <vikas.manocha@st.com>
diff --git a/board/st/stm32f746-disco/stm32f746-disco.c b/board/st/stm32f746-disco/stm32f746-disco.c
index 72212f4..ee1deb5 100644
--- a/board/st/stm32f746-disco/stm32f746-disco.c
+++ b/board/st/stm32f746-disco/stm32f746-disco.c
@@ -380,7 +380,6 @@
 	int res;
 
 	res = uart_setup_gpio();
-	clock_setup(USART1_CLOCK_CFG);
 	if (res)
 		return res;
 
diff --git a/drivers/clk/clk_stm32f7.c b/drivers/clk/clk_stm32f7.c
index 4c5388a..0d86395 100644
--- a/drivers/clk/clk_stm32f7.c
+++ b/drivers/clk/clk_stm32f7.c
@@ -228,9 +228,6 @@
 void clock_setup(int peripheral)
 {
 	switch (peripheral) {
-	case USART1_CLOCK_CFG:
-		setbits_le32(&STM32_RCC->apb2enr, RCC_APB2ENR_USART1EN);
-		break;
 	case GPIO_A_CLOCK_CFG:
 		setbits_le32(&STM32_RCC->ahb1enr, RCC_AHB1ENR_GPIO_A_EN);
 		break;