Add #include <linux/slab.h> to all files that call kzalloc|kmalloc|kfree.

Some architectures, like arm, do not automatically pull in the definitions for
kzalloc and friends. This allows DAHDI to build on those platforms.

Originally reported to the asterisk-users mailing list here
http://lists.digium.com/pipermail/asterisk-users/2014-February/282338.html

Signed-off-by: Shaun Ruffell <sruffell@digium.com>
Acked-by: Tzafrir Cohen <tzafrir.cohen@xorcom.com>
Signed-off-by: Russ Meyerriecks <rmeyerriecks@digium.com>
pciradio: interruptible_sleep_on_timeout() -> msleep_interruptible()

interruptible_sleep_on_timeout() has been deprecated for awhile and was finally
removed in Linux 3.15. Since interruptible_sleep_on_timeout() uses jiffies for
the delay, I assumed that each jiffy equated to 10ms given the age of the
driver.

Signed-off-by: Shaun Ruffell <sruffell@digium.com>
Acked-by: Tzafrir Cohen <tzafrir.cohen@xorcom.com>
Signed-off-by: Russ Meyerriecks <rmeyerriecks@digium.com>
wctc4xxp: Speed up channel setup / tear-down.

1) Enabling multiple csm_encaps channel commands in a single packet.
2) Sending commands to separate channels in parallel.

This reduces the time waiting for the responses to the commands and brings in
the channel setup from 50ms to under 10ms.

Signed-off-by: Shaun Ruffell <sruffell@digium.com>
Signed-off-by: Russ Meyerriecks <rmeyerriecks@digium.com>