wireless-regdb: update rules for US on 2.4/5G

The bands are wider and more continuous:
5.15-5.35 GHz, 5.47-5.725 GHz and 5.725-5.85 GHz.
Based on the April 2, 2020 version of e-CFR Title 47 Part 15,
Radio Frequency Devices.

This also includes a small tweak for channel 144 similar to TW.

Signed-off-by: bkil <b.K.il.h.u+tigbuh@gmail.com>
Signed-off-by: Seth Forshee <seth.forshee@canonical.com>