Patch merged into coreboot/master: xcompile: add riscv64 name to riscv toolchain

the following patch was just integrated into master:
commit 9cc8cb2090741cefb3f3de14b2ad41e6baf2282f
Author: Iru Cai 
Date:   Tue Apr 5 23:43:59 2016 +0800

xcompile: add riscv64 name to riscv toolchain

In newer toolchain with binutils 2.26 and GCC 5.3.0, we build binutils
    and GCC with machine type riscv32 and riscv64 instead of riscv. We can
    see it in this riscv-gnu-toolchain commit:
    https://github.com/riscv/riscv-gnu-toolchain/commit/dedbf07

Signed-off-by: Iru Cai 
    Signed-off-by: Martin Roth 
    Change-Id: Id552859ec256d80108e073d25cd51dd1fc3fbfac
    Reviewed-on: https://review.coreboot.org/14257
    Tested-by: build bot (Jenkins)
    Reviewed-by: Patrick Georgi

See https://review.coreboot.org/14257 for details.

-gerrit