WITHOUT_BOOT build option appears to include stand, failing on libsa

building libsa needs to use -I${LDRSRC} for some files.

PR: 260083
Submitted by: Ivan Rozhuk
Approved by: re (gjb, early MFC)

(cherry picked from commit 9633c3d87476f72375f13942b55a4c9a7a00c7d8)