clk: stm32f7: rename clk_stm32f7.c to clk_stm32f.c

Now that clk_stm32f7.c manages clocks for both STM32F4 and F7 SoCs
rename it to a more generic clk_stm32f.c

Fix also some checkpatch errors/warnings.

Signed-off-by: Patrice Chotard <patrice.chotard@st.com>
Reviewed-by: Vikas Manocha <vikas.manocha@st.com>
diff --git a/drivers/clk/Kconfig b/drivers/clk/Kconfig
index baa60a5..f6644ee 100644
--- a/drivers/clk/Kconfig
+++ b/drivers/clk/Kconfig
@@ -46,6 +46,14 @@
 	help
 	  Enable this to support the clocks
 
+config CLK_STM32F
+	bool "Enable clock driver support for STM32F family"
+	depends on CLK && (STM32F7 || STM32F4)
+	default y
+	help
+	  This clock driver adds support for RCC clock management
+	  for STM32F4 and STM32F7 SoCs.
+
 config CLK_ZYNQ
 	bool "Enable clock driver support for Zynq"
 	depends on CLK && ARCH_ZYNQ