Revert "Add --enable-earlycon option to vm tool"

This reverts commit ec68eaf6e8ba07cf400cdc33501cdd1a85dfe665.

Reason for revert: Droidmonitor created revert due to b/363003807.

Change-Id: I412b0a1a25eb19371c64bce9e489d4eed2ae7b07
diff --git a/guest/pvmfw/src/entry.rs b/guest/pvmfw/src/entry.rs
index 8f9340b..ce04317 100644
--- a/guest/pvmfw/src/entry.rs
+++ b/guest/pvmfw/src/entry.rs
@@ -276,9 +276,8 @@
     MEMORY.lock().as_mut().unwrap().unshare_all_memory();
 
     if let Some(mmio_guard) = get_mmio_guard() {
-        if cfg!(debuggable_vms_improvements) && debuggable_payload {
-            // Keep UART MMIO_GUARD-ed for debuggable payloads, to enable earlycon.
-        } else {
+        // Keep UART MMIO_GUARD-ed for debuggable payloads, to enable earlycon.
+        if !debuggable_payload {
             mmio_guard.unmap(UART_PAGE_ADDR).map_err(|e| {
                 error!("Failed to unshare the UART: {e}");
                 RebootReason::InternalError