ci: remove unused drone configuration

Change-Id: I20bded8111deb122757dbf259d17cd80010c2bb6
Signed-off-by: Jerry Yu <jerry.h.yu@arm.com>

.drone.yml

@@ -1,89 +0,0 @@
-kind: pipeline
-name: arm64-linux-gcc-5.4
-
-platform:
-  os: linux
-  arch: arm64
-
-steps:
-- name: arm64-linux-gcc-5.4
-  image: ubuntu:xenial
-  environment:
-    C_COMPILER: gcc
-  commands:
-  - if [ -n "$C_COMPILER" ]; then export CC="$C_COMPILER"; fi
-  - if [ -n "$AS_ASSEMBL" ]; then export AS="$AS_ASSEMBL"; fi
-  - apt-get -qq update
-  - apt-get install -qq -y build-essential git indent libtool libz-dev yasm autoconf
-  - if [ -n "$CC" ]; then $CC --version; fi
-  - if [ -n "$AS" ]; then $AS --version; fi
-  - ./tools/test_autorun.sh "$TEST_TYPE"
-
----
-kind: pipeline
-name: arm64-linux-gcc-4.7
-
-platform:
-  os: linux
-  arch: arm64
-
-steps:
-- name: arm64-linux-gcc-4.7
-  image: ubuntu:xenial
-  environment:
-    C_COMPILER: gcc-4.7
-  commands:
-  - if [ -n "$C_COMPILER" ]; then export CC="$C_COMPILER"; fi
-  - if [ -n "$AS_ASSEMBL" ]; then export AS="$AS_ASSEMBL"; fi
-  - apt-get -qq update
-  - apt-get install -qq -y build-essential git indent libtool libz-dev software-properties-common yasm autoconf
-  - add-apt-repository -y ppa:ubuntu-toolchain-r/test
-  - apt-get -qq update
-  - apt-get install -qq -y g++-4.7
-  - if [ -n "$CC" ]; then $CC --version; fi
-  - if [ -n "$AS" ]; then $AS --version; fi
-  - ./tools/test_autorun.sh "$TEST_TYPE"
-
----
-kind: pipeline
-name: arm64-linux-gcc-6
-
-platform:
-  os: linux
-  arch: arm64
-
-steps:
-- name: arm64-linux-gcc-6
-  image: debian:9
-  environment:
-    C_COMPILER: gcc
-  commands:
-  - if [ -n "$C_COMPILER" ]; then export CC="$C_COMPILER"; fi
-  - if [ -n "$AS_ASSEMBL" ]; then export AS="$AS_ASSEMBL"; fi
-  - apt-get -q update
-  - apt-get install -y build-essential git indent libtool libz-dev software-properties-common yasm autoconf
-  - if [ -n "$CC" ]; then $CC --version; fi
-  - if [ -n "$AS" ]; then $AS --version; fi
-  - ./tools/test_autorun.sh "$TEST_TYPE"
-
----
-kind: pipeline
-name: arm64-linux-extended-tests
-
-platform:
-  os: linux
-  arch: arm64
-
-steps:
-- name: arm64-linux-extended-tests
-  image: ubuntu:xenial
-  environment:
-    TEST_TYPE: ext
-  commands:
-  - if [ -n "$C_COMPILER" ]; then export CC="$C_COMPILER"; fi
-  - if [ -n "$AS_ASSEMBL" ]; then export AS="$AS_ASSEMBL"; fi
-  - apt-get -qq update
-  - apt-get install -qq -y build-essential git indent libtool libz-dev software-properties-common yasm autoconf
-  - if [ -n "$CC" ]; then $CC --version; fi
-  - if [ -n "$AS" ]; then $AS --version; fi
-  - ./tools/test_autorun.sh "$TEST_TYPE"