test: increase FVP Trusted SRAM where necessary

The TF-A configurations used by some tests require a larger Trusted SRAM
than the 256KB default. This increases the Trusted SRAM of these tests
to 384KB.

Signed-off-by: Chris Kay <chris.kay@arm.com>
Change-Id: If9a09d32472d8db78bd375da343a8feca6f82044
(cherry picked from commit 56d0ff12c2225e8c82b890b20a1b449fc05f3c7e)
diff --git a/tf_config/fvp-tbb-mbedtls-tsp-async-irq2el3 b/tf_config/fvp-tbb-mbedtls-tsp-async-irq2el3
index 0ada492..d8cfbe8 100644
--- a/tf_config/fvp-tbb-mbedtls-tsp-async-irq2el3
+++ b/tf_config/fvp-tbb-mbedtls-tsp-async-irq2el3
@@ -8,3 +8,4 @@
 TRUSTED_BOARD_BOOT=1
 TSP_INIT_ASYNC=1
 TSP_NS_INTR_ASYNC_PREEMPT=1
+FVP_TRUSTED_SRAM_SIZE=384