n9: fix for CMT not working

CMT would fail with WAKLINES TEST FAILED error. The underlying cause
was usage of function irq_to_gpio that returned wrong GPIO number
for a given IRQ number (it returned 87 instead of 151 for cawake IRQ).
Subsequently ssi_wakein function would always inspected wrong GPIO pin
and always retuned "high" causing ssi_wake_tasklet to misbehave.
To avoid this ssi_resources array now contains GPIO number (not only
IRQ) and omap_ssi stores that GPIO number in omap_ssi_port struct as
wake_gpio alongside IRQ number (stored in wake_irq). This removes the
need for irq_to_gpio function.

Signed-off-by: Filip Matijević <filip.matijevic.pz@gmail.com>