Add support for TBBR using ECDSA keys in ARM platforms

    - fixed compile error when KEY_ALG=ecdsa
    - add new option ecdsa for TF_MBEDTLS_KEY_ALG
    - add new option devel_ecdsa for ARM_ROTPK_LOCATION
    - add ecdsa key at plat/arm/board/common/rotpk/
    - reduce the mbedtls heap memory size to 13k

Change-Id: I3f7a6170af93fdbaaa7bf2fffb4680a9f6113c13
Signed-off-by: Qixiang Xu <qixiang.xu@arm.com>
diff --git a/plat/arm/board/common/rotpk/arm_rotpk_ecdsa.der b/plat/arm/board/common/rotpk/arm_rotpk_ecdsa.der
new file mode 100644
index 0000000..2547877
--- /dev/null
+++ b/plat/arm/board/common/rotpk/arm_rotpk_ecdsa.der
Binary files differ
diff --git a/plat/arm/board/common/rotpk/arm_rotpk_ecdsa_sha256.bin b/plat/arm/board/common/rotpk/arm_rotpk_ecdsa_sha256.bin
new file mode 100644
index 0000000..c5e123a
--- /dev/null
+++ b/plat/arm/board/common/rotpk/arm_rotpk_ecdsa_sha256.bin
@@ -0,0 +1 @@
+.@¿nù»˜1q	=ýÑÌiJ˜ë‹ ° †Nl
\ No newline at end of file
diff --git a/plat/arm/board/common/rotpk/arm_rotprivk_ecdsa.pem b/plat/arm/board/common/rotpk/arm_rotprivk_ecdsa.pem
new file mode 100644
index 0000000..fb328e3
--- /dev/null
+++ b/plat/arm/board/common/rotpk/arm_rotprivk_ecdsa.pem
@@ -0,0 +1,5 @@
+-----BEGIN EC PRIVATE KEY-----
+MHcCAQEEINSaX6nvzS3teiBJA7WlTLRKJOajpy29o2cArLbUXoZBoAoGCCqGSM49
+AwEHoUQDQgAEm+ZIvTQ44aKk83DhVLsvsFpKDP/Ch9vA+4Hp+fmVfX6gDH8K1OBi
+SpRf7FJ9RGPIn2H6xst+a1OtLMWUDRqGkQ==
+-----END EC PRIVATE KEY-----