dma: keystone_nav: generalize driver usage

dma: keystone_nav: generalize driver usage

The keystone_nav driver is general driver intended to be used for
working with queue manager and pktdma for different IPs like NETCP,
AIF, FFTC, etc. So the it's API shouldn't be named like it works only
with one of them, it should be general names. The names with prefix
like netcp_* rather do for drivers/net/keystone_net.c driver. So it's
good to generalize this driver to be used for different IP's and
delete confusion with real NETCP driver.

The current netcp_* functions of keystone navigator can be used for
other settings of pktdma, not only for NETCP. The API of this driver
is used by the keystone_net driver to work with NETCP, so net driver
also should be corrected. For convenience collect pkdma
configurations in drivers/dma/keystone_nav_cfg.c.

Acked-by: Vitaly Andrianov <vitalya@ti.com>
Signed-off-by: Ivan Khoronzhuk <ivan.khoronzhuk@ti.com>