haven: Convert the cap entry locks to spinlocks

There's a potential chance that the clients can request to
send or receive the data from an interrupt context. Hence,
convert the cap_entry_lock from mutex to a spinlock.

Change-Id: Ic314a32f7a8007308c0a397e0cc44f16441c58d4
Signed-off-by: Raghavendra Rao Ananta <rananta@codeaurora.org>
Signed-off-by: Murali Nalajala <mnalajal@codeaurora.org>