chore: increase SRAM size

Use FVP_TRUSTED_SRAM_SIZE=384 for fvp-spm-tbb-dualroot tf-a builds.

Change-Id: I395773652f71f655a84a4528746509192116fc45
Signed-off-by: Govindraj Raja <govindraj.raja@arm.com>
diff --git a/tf_config/fvp-spm-tbb-dualroot b/tf_config/fvp-spm-tbb-dualroot
index 6a23ac0..6c87551 100644
--- a/tf_config/fvp-spm-tbb-dualroot
+++ b/tf_config/fvp-spm-tbb-dualroot
@@ -17,3 +17,4 @@
 USE_ROMLIB=1
 GIC_EXT_INTID=1
 PLAT_TEST_SPM=1
+FVP_TRUSTED_SRAM_SIZE=384