[coreboot] Build fails on Thinkpad W520

[Andreas Restle]

Building coreboot for Thinkpad W520 currently fails with the following
error:

CC         romstage/northbridge/intel/sandybridge/raminit_common.o
In file included from src/northbridge/intel/sandybridge/raminit_common.c:18:
src/northbridge/intel/sandybridge/raminit_common.c: In function
'dram_odt_stretch':
src/northbridge/intel/sandybridge/raminit_common.c:211:49: error: 'reg'
undeclared (first use in this function); did you mean 'prog'?
   printram("OTHP Workaround [%x] = %x\n", addr, reg);
                                                 ^~~
src/include/console/console.h:65:31: note: in definition of macro 'printk'
  do { do_printk(LEVEL, fmt, ##args); } while (0)
                               ^~~~
src/northbridge/intel/sandybridge/raminit_common.c:211:3: note: in
expansion of macro 'printram'
   printram("OTHP Workaround [%x] = %x\n", addr, reg);
   ^~~~~~~~
src/northbridge/intel/sandybridge/raminit_common.c:211:49: note: each
undeclared identifier is reported only once for each function it appears in
   printram("OTHP Workaround [%x] = %x\n", addr, reg);
                                                 ^~~
src/include/console/console.h:65:31: note: in definition of macro 'printk'
  do { do_printk(LEVEL, fmt, ##args); } while (0)
                               ^~~~
src/northbridge/intel/sandybridge/raminit_common.c:211:3: note: in
expansion of macro 'printram'
   printram("OTHP Workaround [%x] = %x\n", addr, reg);
   ^~~~~~~~
make: *** [Makefile:339:
build/romstage/northbridge/intel/sandybridge/raminit_common.o] Fehler 1

I've been using coreboot on the W520 for some time now, thanks to
Charlotteplusplus and  Nico Rikken (thank you both!). This is the first
time I encountered this error.

Branch master, freshly pulled of git. Thinkpad W520, 32GB Ram, i7-3940XM
(Ivybridge).

Any help is much appreciated.