Merge tag 'xilinx-kconfig-for-v2018.03' of git://www.denx.de/git/u-boot-microblaze

Xilinx Kconfig changes for v2018.03

- Moving some macros to Kconfig

# gpg: Signature made Thu 01 Mar 2018 10:45:58 AM EST using DSA key ID 294A0C21
# gpg: Good signature from "Michal Simek <monstr@monstr.eu>"
# gpg:                 aka "Michal Simek (Xilinx) <michals@xilinx.com>"
# gpg:                 aka "Michal Simek (Xilinx) <michal.simek@xilinx.com>"