The DPLL USB can generate higher speed (x2) than the regular ones.
The max multiplication value is then twice the previous value.

Fix both max_mult and max_div with that correct values.

Change the max_div variable type to u16 to allow storing up to 256.

Replace as well the define with the value to avoid
unneeded indirection and provide a better readability.

Remove the defines that become useless.
Signed-off-by: Benoit Cousson <b-cousson@ti.com>
Cc: Paul Walmsley <paul@pwsan.com>
Cc: Rajendra Nayak <rnayak@ti.com>
Signed-off-by: Paul Walmsley <paul@pwsan.com>