[arm] Cleanup: use hex for offsets

Changed offset from decimal to hex to match architecture reference
manual terminology and keep coherency with the rest of the code.

Signed-off-by: Torbjörn SVENSSON <torbjorn.svensson@st.com>
Signed-off-by: Yvan Roux <yvan.roux@foss.st.com>
1 file changed