[CORE] vmm_devtree: Fix VMM_DEVTREE_NODEID_TABLE_ENTRY() macro

By mistake, the patch which introduced VMM_DEVTREE_NODEID_TABLE_ENTRY()
macro used "#ifdef __VMM_MODULES__" whereas it should have been
"#ifndef __VMM_MODULES" to indicate that we don't support this macro
for pluggable modules.

My apologies for the unnecessary noise.

Signed-off-by: Anup Patel <anup@brainfault.org>