qemuv8: rust.exp: increase timeout of signature verification to 400s

Since optee_os commit b05636319287 ("Squashed commit upgrading to
mbedtls-3.6.0"), the signature-verification-rs test takes a lot more
time when CFG_CORE_DEBUG_CHECK_STACKS=y. Here are some values reported
by "time signature-verification-rs" on QEMUv8:

  [CFG_CORE_DEBUG_CHECK_STACKS=y]
  Before: 0m 30s ; 0m 39s ; 0m 28s
  After: 3m 8s ; 2m 13s ; 6m 36s ; 4m 14s

  [CFG_CORE_DEBUG_CHECK_STACKS=n]
  Before: 0m 1.55s ; 0m 1.57s ; 0m 1.77s 0m 0.87s
  After: 0m 2.69s ; 0m 1.20s ; 0m 1.61s ; 0m 1.73s

Therefore, increase the timeout for this test specifically.

Signed-off-by: Jerome Forissier <jerome.forissier@linaro.org>
Acked-by: Jens Wiklander <jens.wiklander@linaro.org>

Author: jforissier

rust.exp

@@ -164,6 +164,9 @@ expect {
 
 expect "# "
 info "Running signature_verification-rs...\n"
+# This one can take up to 6 minutes when CFG_CORE_DEBUG_CHECK_STACKS=y
+# (3-4 minutes is common on my machine)
+set timeout 400
 send -- "signature_verification-rs\r"
 expect {
 	"Success" {