arch/x86: Replace some __PRE_RAM__ use

Change-Id: I4d8db430f8cd0bf0f161fc5cef052f153e59e2bc
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/35390
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/include/cpu/x86/cache.h

@@ -84,9 +84,7 @@ static __always_inline void disable_cache(void)
 	wbinvd();
 }
 
-#if !defined(__PRE_RAM__)
 void x86_enable_cache(void);
-#endif
 
 #endif /* !__ASSEMBLER__ */
 #endif /* CPU_X86_CACHE */