Inner kernel function should have same signature as drivers

[skyreflectedinmirrors]

Currently the kernel driver looks like:

__kernel void __attribute__ ((reqd_work_group_size(1, 1, 1))) species_rates_driver(int const problem_size, __global double const *__restrict__ P_arr, __global double const *__restrict__ phi, __global double *__restrict__ dphi, __global double const *__restrict__ rwk)

While the kernel itself is:

__kernel void __attribute__ ((reqd_work_group_size(1, 1, 1))) species_rates(__global double *__restrict__ rwk)

where the local versions of P, phi and dphi have been compressed in to the rwk vector.

We need to modify the kernel to look like:

__kernel void __attribute__ ((reqd_work_group_size(1, 1, 1))) species_rates(__global double const *__restrict__ P_arr, __global double const *__restrict__ phi, __global double *__restrict__ dphi, __global double const *__restrict__ rwk)

for simplicity / clarity, even if those arrays are part of rwk in the driver.

Additionally -- cleaning up the pointer unpacks to those necessary for the owning kernel & excluding the P, phi and dphi unpacks.

[skyreflectedinmirrors]

Fixed by work on the old kernel_gen_rewrite branch (and on-going from aaff8e587856d89c69422bacbd03c5b2d98fac51)