[media] s5k5baf: allow to handle arbitrary long i2c sequences

Using variable length array in s5k5baf_write_arr_seq caused
an implicit assumption that i2c sequences should be short.
The patch rewrites the function so it can handle sequences
of any length and does not use variable length array.

Reported-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Andrzej Hajda <a.hajda@samsung.com>
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Mauro Carvalho Chehab <m.chehab@samsung.com>