dmaengine: ste_dma40: Remove unnecessary call to d40_phy_cfg()

The majority of configuration done in d40_phy_config() pertains
to physical channels. Move the call over to runtime config which
has different code paths for physical and logical channels already,
and make it an exclusive physical channel config function as the
name implies, and drop the is_log argument.

Since we moved the call to runtime_config() it only gets called
for device transfers, so encode the small snippet of configuration
pertaining to memcpy channels into the d40_config_memcpy()
function.

Acked-by: Vinod Koul <vinod.koul@intel.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
[rewrote the commit message]
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>