Changed atoi and atohex to $sscanf as per LRM 6.16.9
Created by: silabs-hfegran
atoi and atohex sign-extends and truncates without warning, Incorrect behavior when address width >32 bits or MSB=1
(setting TEST_PLUSARGS=+nmi_addr=0xbc000100
replicates the problem this commit fixes)
Signed-off-by: Henrik Fegran Henrik.Fegran@silabs.com