build: Change travis osx to use std brew

The osx brew and older linux targets are failing the update.
This removes the older linux builds and change the osx to
take the latest brew that comes with the image instead of
doing a brew update on every build.

Change-Id: Ib1543296a733875c9eff798326b0d45854153923
Signed-off-by: Greg Tucker <greg.b.tucker@intel.com>

.travis.yml

@@ -4,10 +4,16 @@ matrix:
   include:
     ### OS X
     - os: osx
+      osx_image: xcode12.5
+      addons:
+        homebrew:
+          packages:
+            - nasm
       env: C_COMPILER=clang
 
     ### linux gcc and format check
-    - dist: xenial
+    - os: linux
+      dist: bionic
       addons:
         apt:
           packages:
@@ -21,58 +27,41 @@ matrix:
       env: C_COMPILER=gcc
 
     ### linux clang
-    - dist: xenial
+    - os: linux
+      dist: bionic
       addons:
         apt:
           packages:
             - nasm
       env: C_COMPILER=clang
 
-    ### linux newer clang
-    - dist: trusty
-      addons:
-        apt:
-          sources:
-            - ubuntu-toolchain-r-test
-            - llvm-toolchain-trusty-4.0
-          packages:
-            - clang-4.0
-      env: C_COMPILER=clang-4.0
-
     ### linux older gcc
-    - dist: trusty
+    - os: linux
+      dist: xenial
       addons:
         apt:
           sources:
             - ubuntu-toolchain-r-test
           packages:
             - g++-4.7
+            - nasm
       env: C_COMPILER=gcc-4.7
 
-    ### linux newer gcc
-    - dist: trusty
-      addons:
-        apt:
-          sources:
-            - ubuntu-toolchain-r-test
-          packages:
-            - g++-6
-      env: C_COMPILER=gcc-6
-
     ### arm64: gcc-5.4
     - os: linux
-      dist: xenial
+      dist: bionic
       arch: arm64
       env: C_COMPILER=gcc
 
     ### arm64: gcc-5.4 extended tests
     - os: linux
-      dist: xenial
+      dist: bionic
       arch: arm64
       env: TEST_TYPE=ext
 
     ### linux extended tests
-    - dist: xenial
+    - os: linux
+      dist: xenial
       addons:
         apt:
           sources:
@@ -90,9 +79,6 @@ before_install:
 
 before_script:
   - if [ $TRAVIS_OS_NAME = linux ]; then sudo apt-get -q update; fi
-  - if [ $TRAVIS_OS_NAME = linux ]; then sudo apt-get install yasm; fi
-  - if [ $TRAVIS_OS_NAME = osx ]; then brew update; fi
-  - if [ $TRAVIS_OS_NAME = osx ]; then brew install yasm; fi
 
 script:
   - if [ -n "${CC}" ]; then $CC --version; fi