stm32f0: rcc: Enable prefetch buffer in rcc_clock_setup_*()

Prefetch buffer makes the code execution from the Flash memory faster.

Signed-off-by: Adam Heinrich <adam@adamh.cz>

lib/stm32/f0/rcc.c

@@ -543,6 +543,7 @@ void rcc_clock_setup_in_hse_8mhz_out_48mhz(void)
 	rcc_set_hpre(RCC_CFGR_HPRE_NODIV);
 	rcc_set_ppre(RCC_CFGR_PPRE_NODIV);
 
+	flash_prefetch_buffer_enable();
 	flash_set_ws(FLASH_ACR_LATENCY_024_048MHZ);
 
 	/* PLL: 8MHz * 6 = 48MHz */
@@ -570,6 +571,7 @@ void rcc_clock_setup_in_hsi_out_48mhz(void)
 	rcc_set_hpre(RCC_CFGR_HPRE_NODIV);
 	rcc_set_ppre(RCC_CFGR_PPRE_NODIV);
 
+	flash_prefetch_buffer_enable();
 	flash_set_ws(FLASH_ACR_LATENCY_024_048MHZ);
 
 	/* 8MHz * 12 / 2 = 48MHz */
@@ -595,6 +597,7 @@ void rcc_clock_setup_in_hsi48_out_48mhz(void)
 	rcc_set_hpre(RCC_CFGR_HPRE_NODIV);
 	rcc_set_ppre(RCC_CFGR_PPRE_NODIV);
 
+	flash_prefetch_buffer_enable();
 	flash_set_ws(FLASH_ACR_LATENCY_024_048MHZ);
 
 	rcc_set_sysclk_source(RCC_HSI48);