travis.yml: Switch to bionic for the host distribution

To match what we're doing in GitLab, move to 'bionic' for these builds
as well.
Signed-off-by: NTom Rini <trini@konsulko.com>

.travis.yml

@@ -4,7 +4,7 @@
 # build U-Boot on Travis CI - https://travis-ci.org/
 
 sudo: required
-dist: xenial
+dist: bionic
 
 language: c
 
@@ -12,7 +12,7 @@ addons:
   apt:
     sources:
     - ubuntu-toolchain-r-test
-    - llvm-toolchain-xenial-7
+    - llvm-toolchain-bionic-7
     packages:
     - cppcheck
     - sloccount
@@ -52,12 +52,13 @@ install:
  - pip install pytest==2.8.7
  - pip install python-subunit
  - pip install pyelftools
- - grub-mkimage -o ~/grub_x86.efi -O i386-efi normal  echo lsefimmap lsefi lsefisystab efinet tftp minicmd
- - grub-mkimage -o ~/grub_x64.efi -O x86_64-efi normal  echo lsefimmap lsefi lsefisystab efinet tftp minicmd
+ - grub-mkimage --prefix="" -o ~/grub_x86.efi -O i386-efi normal  echo lsefimmap lsefi lsefisystab efinet tftp minicmd
+ - grub-mkimage --prefix="" -o ~/grub_x64.efi -O x86_64-efi normal  echo lsefimmap lsefi lsefisystab efinet tftp minicmd
  - mkdir ~/grub2-arm
  - ( cd ~/grub2-arm; wget -O - http://download.opensuse.org/ports/armv7hl/distribution/leap/42.2/repo/oss/suse/armv7hl/grub2-arm-efi-2.02~beta2-87.1.armv7hl.rpm | rpm2cpio | cpio -di )
  - mkdir ~/grub2-arm64
  - ( cd ~/grub2-arm64; wget -O - http://download.opensuse.org/ports/aarch64/distribution/leap/42.2/repo/oss/suse/aarch64/grub2-arm64-efi-2.02~beta2-87.1.aarch64.rpm | rpm2cpio | cpio -di )
+ - wget http://mirrors.kernel.org/ubuntu/pool/main/m/mpfr4/libmpfr4_3.1.4-1_amd64.deb && sudo dpkg -i libmpfr4_3.1.4-1_amd64.deb && rm libmpfr4_3.1.4-1_amd64.deb
 
 env:
   global: