Patch merged into coreboot/master: arch/riscv: Move _start to the beginning of the bootblock

the following patch was just integrated into master:
commit 719f9b53898bffa52395a1e25b616432eef6ff57
Author: Jonathan Neuschäfer 
Date:   Tue Jun 21 19:37:03 2016 +0200

arch/riscv: Move _start to the beginning of the bootblock

The different entry points (0x100, 0x140, ...), which were defined in
    the RISC-V Privileged Specification 1.7, aren't used anymore. Instead
    the Spike bootrom jumps at the start of our image, and traps are handled
    through mtvec.

Change-Id: I865adec5e7a752a25bac93a45654ac06e27d5a8e
    Signed-off-by: Jonathan Neuschäfer 
    Reviewed-on: https://review.coreboot.org/15283
    Tested-by: build bot (Jenkins)
    Reviewed-by: Ronald G. Minnich

See https://review.coreboot.org/15283 for details.

-gerrit