boot/arm-trusted-firmware: bump to v2.12

For change log, see [1].

Update trusted-firmware-a version to v2.12 and add a hash file
accordingly.

Compared to v2.11, the license has changed with the additional mention
of files from the pydevicetree project under Apache 2.0 license.
As we only document the main license of TF-A, BSD-3-Clause, this change
has no impact for us.

[1] https://git.trustedfirmware.org/plugins/gitiles/TF-A/trusted-firmware-a.git/+/refs/tags/v2.12/docs/change-log.md

Signed-off-by: Vincent Stehlé <vincent.stehle@arm.com>
Cc: Dick Olsson <hi@senzilla.io>
Cc: Sergey Matyukevich <geomatsi@gmail.com>
[Julien:
  - add link to change log
  - remove v2.11 hash file
]
Signed-off-by: Julien Olivain <ju.o@free.fr>

boot/arm-trusted-firmware/Config.in

@@ -14,7 +14,7 @@ choice
 	  Select the specific ATF version you want to use
 
 config BR2_TARGET_ARM_TRUSTED_FIRMWARE_LATEST_VERSION
-	bool "v2.11"
+	bool "v2.12"
 
 config BR2_TARGET_ARM_TRUSTED_FIRMWARE_LATEST_LTS_2_10_VERSION
 	bool "latest lts-v2.10.x"
@@ -52,7 +52,7 @@ config BR2_TARGET_ARM_TRUSTED_FIRMWARE_CUSTOM_VERSION_VALUE
 
 config BR2_TARGET_ARM_TRUSTED_FIRMWARE_VERSION
 	string
-	default "v2.11"		if BR2_TARGET_ARM_TRUSTED_FIRMWARE_LATEST_VERSION
+	default "v2.12"		if BR2_TARGET_ARM_TRUSTED_FIRMWARE_LATEST_VERSION
 	default "lts-v2.10.5"	if BR2_TARGET_ARM_TRUSTED_FIRMWARE_LATEST_LTS_2_10_VERSION
 	default "lts-v2.8.20"	if BR2_TARGET_ARM_TRUSTED_FIRMWARE_LATEST_LTS_2_8_VERSION
 	default "custom"	if BR2_TARGET_ARM_TRUSTED_FIRMWARE_CUSTOM_TARBALL

boot/arm-trusted-firmware/v2.11/arm-trusted-firmware.hash

@@ -1,3 +0,0 @@
-# Locally calculated
-sha256  c0f23ccc71c49989e9ad238acf334473c17b7c88f79a20c829c3d443e3794a22  arm-trusted-firmware-v2.11-git4.tar.gz
-sha256  03d5088ff4fbfe989f3c807117356191c263cf27d62ee6916bde8532611728ed  docs/license.rst

boot/arm-trusted-firmware/v2.12/arm-trusted-firmware.hash

@@ -0,0 +1,3 @@
+# Locally calculated
+sha256  06b35a3596b8417bf66f7bfdd7acd181bcb53fc36dc13216227b5cae154e0219  arm-trusted-firmware-v2.12-git4.tar.gz
+sha256  b2c79635797bafcde84c6edadadde290b9d5e05deb3ea16a847210fd2ca83669  docs/license.rst