net/qede/base: revise management FW mbox access scheme

net/qede/base: revise management FW mbox access scheme

Revise the manamgement FW mbox access locking scheme for the access to the
MFW mailbox:
 - add a new linked list called cmd_list to ecore_mcp_info that tracks all
   the mailbox commands sent to management FW and ones waiting for
   response.
 - add a mutex lock called cmd_lock to ecore_mcp_info, a spinlock used to
   serialize the access to this cmd_list and makes sure that the mbox is
   not a pending one before sending a new mbox request. It protects the
   access to the mailbox commands list and sending of the commands.
 - add ecore_mcp_cmd_add|del|get_elem() APIs for new access scheme
 - remove ecore_mcp_mb_lock() and ecore_mcp_mb_unlock()
 - add a mutex lock called link_lock to ecore_mcp_info, a spinlock used for
   syncing SW link-changes and link-changes originating from attention
   context. This locking scheme prevents possible race conditions that may
   occur, such as during link status reporting.
 - Surround OSAL_{MUTEX,SPIN_LOCK}_{ALLOC,DEALLOC} with
   '#ifdef CONFIG_ECORE_LOCK_ALLOC'. In case memory has to be allocated for
   lock primitives, then compile driver with CONFIG_ECORE_LOCK_ALLOC flag.

Signed-off-by: Rasesh Mody <rasesh.mody@cavium.com>