board: compal: paz00: clean up the board

Since implementation of pinctrl driver for T20 Paz00 can switch
to device tree pinmux setup along with remove of board pinmux
and some minor device tree and defconfig tweaks.

Tested-by: Agneli <poczt@protonmail.ch> # Toshiba AC100 T20
Signed-off-by: Svyatoslav Ryhel <clamor95@gmail.com>