arch-stm32: Factorize stm32.h for STM32F4 and F7

For STM32F4 and F7 SoCx family, a specific stm32.h file exists.
Some common defines are duplicated or even unused in each of
these stm32.h.

Factorize all common definition in arch/arm/include/asm/stm32f.h and keep
specific definitions in each arch/arm/include/asm/arch-stm32fx/stm32.h.

Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
diff --git a/arch/arm/include/asm/arch-stm32/stm32f.h b/arch/arm/include/asm/arch-stm32/stm32f.h
new file mode 100644
index 0000000..7bea20b
--- /dev/null
+++ b/arch/arm/include/asm/arch-stm32/stm32f.h
@@ -0,0 +1,22 @@
+/*
+ * Copyright (C) 2018, STMicroelectronics - All Rights Reserved
+ * Author(s): Patrice Chotard, <patrice.chotard@st.com> for STMicroelectronics.
+ *
+ * SPDX-License-Identifier:	GPL-2.0+
+ */
+
+#ifndef _ASM_ARCH_STM32F_H
+#define _ASM_ARCH_STM32F_H
+
+#define STM32_PERIPH_BASE	0x40000000UL
+
+#define STM32_APB2_PERIPH_BASE	(STM32_PERIPH_BASE + 0x00010000)
+#define STM32_AHB1_PERIPH_BASE	(STM32_PERIPH_BASE + 0x00020000)
+
+#define STM32_SYSCFG_BASE	(STM32_APB2_PERIPH_BASE + 0x3800)
+#define STM32_FLASH_CNTL_BASE	(STM32_AHB1_PERIPH_BASE + 0x3C00)
+
+void stm32_flash_latency_cfg(int latency);
+
+#endif /* _ASM_ARCH_STM32F_H */
+