pico-imx7d: enable boot without PMIC

If PMIC is not probed successfully, it is still OK to boot
with default configuration although power is not optimized.

Default voltage of SW1A/SW1B is 1.1V/1.0V for PC32PF3000A1EP
on pico according to table 42 of spec of PF3000 ver 9.0.

Default mode of SW1A/SW1B is APS as expected(table 47).

Signed-off-by: Jun Nie <jun.nie@linaro.org>