pinctrl: i.MX27: Remove nonexistent pad definitions

Pads for PB0-PB3, PC0-PC4, PE26-PE31 and PF24-PF31 does not exist on
the i.MX27 SOC. There is no reason to define them, the presence of
such definitions in the DTS files is a bug.
This patch removes these nonexistent pad definitions.

Signed-off-by: Alexander Shiyan <shc_work@mail.ru>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>