spmi-pmic-arb: correct offset of debug registers for v2.2

Two registers which are used for debugging have different offset
in pmic-arbiter versions 2.2 vs earlier versiosn.

Change-Id: If072e280c2207b07b637b9ed048fd350c541e07d
Signed-off-by: Gilad Avidov <gavidov@codeaurora.org>