[S] Change in coreboot[master]: arch/riscv/mcall.h: Fix building with clang

[Arthur Heymans (Code Review)]

Attention is currently required from: Arthur Heymans, Philipp Hug, ron minnich.

Arthur Heymans has uploaded a new patch set (#14) to the change originally created by Arthur Heymans. ( https://review.coreboot.org/c/coreboot/+/63072 )

Change subject: arch/riscv/mcall.h: Fix building with clang
......................................................................

arch/riscv/mcall.h: Fix building with clang

Having multiple statements hidden inside a macro that supposedly
returns a pointer does not work well with clang. Moving the stack
register to a global variable fixes this.

Change-Id: If24b2766404b892a006926f0cd45771ceebf1275
Signed-off-by: Arthur Heymans 
---
M src/arch/riscv/include/mcall.h
1 file changed, 17 insertions(+), 2 deletions(-)

git pull ssh://review.coreboot.org:29418/coreboot refs/changes/72/63072/14