dmaengine: ste_dma40: Remove 'always true' checking

Before allocating memory for logical channels, the current driver
checks to see if there are any. Well as the dma40_memcpy_channels[]
array is always populated, the check is always true. Best to
remove the check.

Cc: Dan Williams <djbw@fb.com>
Cc: Per Forlin <per.forlin@stericsson.com>
Cc: Rabin Vincent <rabin@rab.in>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Lee Jones <lee.jones@linaro.org>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>