treewide: Replace CONFIG(ARCH_xx) tests

Once we support building stages for different architectures,
such CONFIG(ARCH_xx) tests do not evaluate correctly anymore.

Change-Id: I599995b3ed5c4dfd578c87067fe8bfc8c75b9d43
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/42183
Reviewed-by: Raul Rangel <rrangel@chromium.org>
Reviewed-by: Furquan Shaikh <furquan@google.com>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/include/symbols.h

@@ -63,7 +63,7 @@ DECLARE_REGION(bl31)
  * (Does not necessarily mean that the memory is accessible.) */
 static inline int preram_symbols_available(void)
 {
-	return !CONFIG(ARCH_X86) || ENV_ROMSTAGE_OR_BEFORE;
+	return !ENV_X86 || ENV_ROMSTAGE_OR_BEFORE;
 }
 
 #endif /* __SYMBOLS_H */