cpu/x86/64bit/exit32.inc: Don't invalidate cache in CAR

Change-Id: I4a4e988d38b548e1c88ffcc5f5ada2e91ff6ba91
Signed-off-by: Patrick Rudolph <patrick.rudolph@9elements.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/48178
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>

src/cpu/x86/64bit/exit32.inc

@@ -23,9 +23,10 @@
 #endif
 
 drop_longmode:
+#if !ENV_CACHE_AS_RAM
 	/* Ensure cache is clean. */
 	wbinvd
-
+#endif
 	/* Set  32-bit code segment and ss */
 	mov	$CODE_SEG, %rcx
 	/* SetCodeSelector32 will drop us to protected mode on return */