arm64: dts: sdm845-mtp: Reserve reserved gpios

With the introduction of commit 3edfb7bd

 ("gpiolib: Show correct
direction from the beginning") the gpiolib will attempt to read the
direction of all pins, which triggers a read from protected register
regions.

The pins 0 through 3 and 81 through 84 are protected, so mark these as
reserved.

Signed-off-by: Bjorn Andersson <bjorn.andersson@linaro.org>
Reviewed-by: Stephen Boyd <sboyd@kernel.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Andy Gross <andy.gross@linaro.org>