fix(hftest): revert uart control for SPMC tests

Signed-off-by: J-Alves <joao.alves@arm.com>
Change-Id: I299ee89fd67f8ec884be14be0b24caddbbefe6f8
diff --git a/BUILD.gn b/BUILD.gn
index a308cee..7bef36c 100644
--- a/BUILD.gn
+++ b/BUILD.gn
@@ -90,7 +90,6 @@
     plat_prng = "//src/arch/aarch64/plat/prng:prng"
     secure_world = "1"
     pl011_base_address = "0x1c090000"
-    hftest_ctrl = "//test/hftest:ctrl_uart"
     smmu_base_address = "0x2b400000"
     smmu_memory_size = "0x100000"
   }