CBMEM: Do not use get_top_of_ram() with DYNAMIC_CBMEM

The name was always obscure and confusing. Instead define cbmem_top()
directly in the chipset code for x86 like on ARMs.

TODO: Check TSEG alignment, it used for MTRR programming.

Change-Id: Ibbe5f05ab9c7d87d09caa673766cd17d192cd045
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: http://review.coreboot.org/7888
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@google.com>

src/arch/x86/boot/cbmem.c

@@ -57,23 +57,20 @@ void set_top_of_ram(uint64_t ramtop)
 }
 #endif /* !__PRE_RAM__ */
 
-#if IS_ENABLED(CONFIG_LATE_CBMEM_INIT)
 unsigned long __attribute__((weak)) get_top_of_ram(void)
 {
 	printk(BIOS_WARNING, "WARNING: you need to define get_top_of_ram() for your chipset\n");
 	return 0;
 }
-#endif
-
-#else
 
+#if IS_ENABLED(CONFIG_DYNAMIC_CBMEM)
 void *cbmem_top(void)
 {
 	/* Top of cbmem is at lowest usable DRAM address below 4GiB. */
 	return (void *)get_top_of_ram();
 }
-
-#endif /* DYNAMIC_CBMEM */
+#endif
+#endif /* !DYNAMIC_CBMEM */
 
 void cbmem_run_init_hooks(void)
 {