The Pico Display 2 example specifies a baud of 74 * 1000 * 1000.
However, the highest baud the Raspberry Pi Pico can achieve is
62,500,000.
I checked and even when the baud of 74 * 1000 * 1000 is specified,
it ends up using the max that the Raspberry Pi Pico can handle anyway.
This commit removes the incorrect baud parameter, using the default
parameter instead.