boards/generic: update offsets for riscv

Signed-off-by: Adam Wujek <adam.wujek@creotech.pl>
3 jobs from adam-riscv in 34 seconds (queued for 3 seconds)
Status Job ID Name Coverage
  Compile
failed #2610
wrs_sw
make_all

00:34

failed #2611
wrs_sw
make_rt_cpu

00:34

failed #2609
wrs_sw
make_wrpc_sw

00:34