Fix IPMI SEL reservations and cancellations

Per the IPMI Spec, the SEL must be reserved to
   Delete an entry
   Clear the SEL
   Get a partial entry
   Add a partial entry

The current SEL reservation must be cancelled when
   A SEL entry is added
   A SEL entry is deleted
   The SEL is cleared
   The device is reset
   A new reservation is requested

This change adds a reservation status to track when a reservation
is active and a method to cancel the current reservation, and it
uses that to cancel the reservation in the Delete, Clear, and Add
SEL methods.

Change-Id: Ifd72e6d06ecc622855bd9ce8cc3928cbd0f2c34b
Signed-off-by: Jason M. Bills <jason.m.bills@linux.intel.com>
3 files changed