Update Get SM Signal command for front panel buttons

This change updates the Get SM Signal command to use the power
control Button service instead of the GPIO daemon to mask and
read the front panel buttons.

This change also updates the Get SM Signal command to the new API.

Tested:
Tested the Get SM Signal IPMI commands to verify that the front panel
    buttons can be masked and read:
    power button:
    ipmitool raw 0x30 0x14 0 0 0
    00
    ipmitool raw 0x30 0x14 0 0 1
    00
    ipmitool raw 0x30 0x14 0 0 0
    01
    ipmitool raw 0x30 0x14 0 0 2
    00

    reset button:
    ipmitool raw 0x30 0x14 1 0 0
    00
    ipmitool raw 0x30 0x14 1 0 1
    00
    ipmitool raw 0x30 0x14 1 0 0
    01
    ipmitool raw 0x30 0x14 1 0 2
    00

    nmi button:
    ipmitool raw 0x30 0x14 3 0 0
    00
    ipmitool raw 0x30 0x14 3 0 1
    00
    ipmitool raw 0x30 0x14 3 0 0
    01
    ipmitool raw 0x30 0x14 3 0 2
    00

Change-Id: Idbb1be30b22d653f8805e1f8addf18a197dc4ee5
Signed-off-by: Jason M. Bills <jason.m.bills@linux.intel.com>
2 files changed