toolchain: update to GCC 9.2

Updates the toolchain to Arm's GCC 9.2 [1]. Note the following
difference compared to the previous release (8.3), which is documented
in the release notes:

 "Changed toolchain naming convention to match standard target triplet
  naming convention, with vendor name being none."

For example, arm-linux-gnueabihf-gcc is now arm-none-linux-gnueabihf-gcc
and aarch64-linux-gnu-gcc is now aarch64-none-linux-gnu-gcc.

This renaming seems pretty much specific to the Arm build of GCC, and
the latest Debian and Ubuntu distributions provide GCC 9.x or 10.x
cross-compilers with the usual naming convention.

Therefore, and to limit the impact of the name change, let's simply
create symbolic links after the toolchain packages are extracted.

Link: [1] https://developer.arm.com/tools-and-software/open-source-software/developer-tools/gnu-toolchain/gnu-a/downloads
Signed-off-by: Jerome Forissier <jerome@forissier.org>
Tested-by: Jerome Forissier <jerome@forissier.org> (QEMU, QEMUv8, HiKey, HiKey960)
Acked-by: Jens Wiklander <jens.wiklander@linaro.org>
Reviewed-by: Etienne Carriere <etienne.carriere@linaro.org>
Tested-by: Etienne Carriere <etienne.carriere@linaro.org> (stm32mp1)
diff --git a/toolchain.mk b/toolchain.mk
index 9a835e3..df85216 100644
--- a/toolchain.mk
+++ b/toolchain.mk
@@ -6,13 +6,13 @@
 
 AARCH32_PATH 			?= $(TOOLCHAIN_ROOT)/aarch32
 AARCH32_CROSS_COMPILE 		?= $(AARCH32_PATH)/bin/arm-linux-gnueabihf-
-AARCH32_GCC_VERSION 		?= gcc-arm-8.3-2019.03-x86_64-arm-linux-gnueabihf
-SRC_AARCH32_GCC 		?= https://developer.arm.com/-/media/Files/downloads/gnu-a/8.3-2019.03/binrel/${AARCH32_GCC_VERSION}.tar.xz
+AARCH32_GCC_VERSION 		?= gcc-arm-9.2-2019.12-x86_64-arm-none-linux-gnueabihf
+SRC_AARCH32_GCC 		?= https://developer.arm.com/-/media/Files/downloads/gnu-a/9.2-2019.12/binrel/$(AARCH32_GCC_VERSION).tar.xz
 
 AARCH64_PATH 			?= $(TOOLCHAIN_ROOT)/aarch64
 AARCH64_CROSS_COMPILE 		?= $(AARCH64_PATH)/bin/aarch64-linux-gnu-
-AARCH64_GCC_VERSION 		?= gcc-arm-8.3-2019.03-x86_64-aarch64-linux-gnu
-SRC_AARCH64_GCC 		?= https://developer.arm.com/-/media/Files/downloads/gnu-a/8.3-2019.03/binrel/${AARCH64_GCC_VERSION}.tar.xz
+AARCH64_GCC_VERSION 		?= gcc-arm-9.2-2019.12-x86_64-aarch64-none-linux-gnu
+SRC_AARCH64_GCC 		?= https://developer.arm.com/-/media/Files/downloads/gnu-a/9.2-2019.12/binrel/$(AARCH64_GCC_VERSION).tar.xz
 
 # Download toolchain macro for saving some repetition
 # $(1) is $AARCH.._PATH		: i.e., path to the destination
@@ -24,6 +24,7 @@
 		echo "Downloading $(3) ..."; \
 		curl -s -L $(2) -o $(TOOLCHAIN_ROOT)/$(3).tar.xz; \
 		tar xf $(TOOLCHAIN_ROOT)/$(3).tar.xz -C $(1) --strip-components=1; \
+		(cd $(1)/bin && for f in *-none-linux*; do ln -s $$f $${f//-none} ; done;) \
 	fi
 endef