[formal] Add assumption for TLUL

FPV found a countercase due to insufficient constraints. Temp convert
the assertion to assumption.
diff --git a/hw/formal/fpv.tcl b/hw/formal/fpv.tcl
index e0be100..924b3b5 100644
--- a/hw/formal/fpv.tcl
+++ b/hw/formal/fpv.tcl
@@ -80,6 +80,7 @@
 assume -from_assert -remove_original -regexp {^\w*\.tlul_assert_host\w*\.legalAOpcode}
 assume -from_assert -remove_original -regexp {^\w*\.tlul_assert_host\w*\.legalAParam}
 assume -from_assert -remove_original -regexp {^\w*\.tlul_assert_host\w*\.sizeMatchesMask}
+assume -from_assert -remove_original -regexp {^\w*\.tlul_assert_host\w*\.sizeGTEMask}
 assume -from_assert -remove_original -regexp {^\w*\.tlul_assert_host\w*\.onlyOnePendingReqPerSourceID}
 assume -from_assert -remove_original -regexp {^\w*\.tlul_assert_host\w*\.addressAlignedToSize}
 assume -from_assert -remove_original -regexp {^\w*\.tlul_assert_host\w*\.maskMustBeContiguous}