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
diff --git a/tf_config/fvp-tspd-tbb-mbedtls-rsa-4k-cert b/tf_config/fvp-tspd-tbb-mbedtls-rsa-4k-cert
index 32d173a..cac4248 100644
--- a/tf_config/fvp-tspd-tbb-mbedtls-rsa-4k-cert
+++ b/tf_config/fvp-tspd-tbb-mbedtls-rsa-4k-cert
@@ -6,3 +6,4 @@
 SPD=tspd
 TRUSTED_BOARD_BOOT=1
 KEY_SIZE=4096
+FVP_TRUSTED_SRAM_SIZE=384