fix: increase TSRAM of `fvp-tspd-tbb-mbedtls-tsp-dram-no-cohmem`

This build job is currently failing due to a lack of available Trusted
SRAM.

Signed-off-by: Chris Kay <chris.kay@arm.com>
Change-Id: Id617ccdd38399ac5eaf0e715cae00bdc27fb6fce
diff --git a/tf_config/fvp-tspd-tbb-mbedtls-tsp-dram-no-cohmem b/tf_config/fvp-tspd-tbb-mbedtls-tsp-dram-no-cohmem
index a49bc71..cd25207 100644
--- a/tf_config/fvp-tspd-tbb-mbedtls-tsp-dram-no-cohmem
+++ b/tf_config/fvp-tspd-tbb-mbedtls-tsp-dram-no-cohmem
@@ -1,6 +1,7 @@
 ARM_ROTPK_LOCATION=devel_rsa
 ARM_TSP_RAM_LOCATION=dram
 CROSS_COMPILE=aarch64-none-elf-
+FVP_TRUSTED_SRAM_SIZE=384
 GENERATE_COT=1
 PLAT=fvp
 SPD=tspd