staging: vt6656: Refactor the vnt_update_pre_ed_threshold function

Create three arrays with the threshold data use in the switch statement
of the vnt_update_pre_ed_threshold function. These three arrays contains
elements of struct vnt_threshold new type.

Create a for loop in the vnt_update_pre_ed_threshold function to do
exactly the same that the if-elseif-else statements in the switch
statement.

Also, remove the if check against the !cr_201 && !cr_206 due to now it
is replace by the NULL check against the threshold pointer. When this
pointer is NULL means that the cr_201 and cr_206 variables have not been
assigned, that is the same that the old comparison against cr_201 and
cr_206 due to these variables were initialized with 0.

The statistics of the old baseband object file are:

section              size   addr
.text                3415      0
.data                 576      0
.bss                    0      0
.rodata               120      0
.comment               45      0
.note.GNU-stack         0      0
.note.gnu.property     28      0
Total                4184

The statistics of the new baseband object file are:

section              size   addr
.text                2209      0
.data                 576      0
.bss                    0      0
.rodata               344      0
.comment               45      0
.note.GNU-stack         0      0
.note.gnu.property     28      0
Total                3202

With this refactoring it increase a little the readonly data but it
decrease much more the .text section. This refactoring decrease the
footprint and makes the code more clear.

Signed-off-by: Oscar Carter <oscar.carter@gmx.com>
Reviewed-by: Quentin Deslandes <quentin.deslandes@itdev.co.uk>
Link: https://lore.kernel.org/r/20200328181706.14276-1-oscar.carter@gmx.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>