regulator: pfuze100: Fix address of FABID

According to the datasheet, the address of FABID is 0x4. Fix it.

Signed-off-by: Axel Lin <axel.lin@ingics.com>
Acked-by: Robin Gong <b38343@freescale.com>
Signed-off-by: Mark Brown <broonie@linaro.org>
Cc: stable@vger.kernel.org