[ALSA] ice1712 - Provides specified midi port names instead of defaults

Patch provides for the ice1712 card driver to overwrite the midi port name
string given by default in mpu401_uart, with one specified in
snd_ice1712_card_info.

Signed-off-by: Alan Horstmann <gineera@aspect135.co.uk>
Signed-off-by: Takashi Iwai <tiwai@suse.de>