cpu/x86/lapic: Refactor timer_fsb()

Common apic_timer code in cpu/x86 should not depend on
intel header files.

Change-Id: Ib099921d4b8e561daea47219385762bb00fc4548
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/34091
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-by: Marshall Dawson <marshalldawson3rd@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/include/cpu/intel/fsb.h

@@ -15,15 +15,7 @@
 #define CPU_INTEL_FSB_H
 
 /*
- * This function returns:
- *	the system bus speed value in MHz
- *	-1 if FSB is not found
- *	-2 if the CPU is not supported
- */
-int get_ia32_fsb(void);
-
-/*
- * This function returns round up 3 * get_ia32_fsb()
+ * This function returns round up 3 * get_timer_fsb()
  */
 int get_ia32_fsb_x3(void);
 

src/include/delay.h

@@ -1,6 +1,17 @@
 #ifndef DELAY_H
 #define DELAY_H
 
+#include <stdint.h>
+
+#if CONFIG_UDELAY_LAPIC_FIXED_FSB != 0
+static inline u32 get_timer_fsb(void)
+{
+	return CONFIG_UDELAY_LAPIC_FIXED_FSB;
+}
+#else
+u32 get_timer_fsb(void);
+#endif
+
 void init_timer(void);
 
 void udelay(unsigned int usecs);