CHROMIUM: arm64: dts: qcs404-mistral: Add gpio-line-names.

Added required gpio-line-names to use gpio hog mechanism.

BUG=b:123667306
TEST=Check kernel build successful for dtb parsing.
     Check gpioinfo command(userspace) output for the gpio names.

Signed-off-by: Santhosh Hassan <sahassan@google.com>
Change-Id: I0e74a8681d0b3761de09529e5d8755f8a57e404c
Reviewed-on: https://chromium-review.googlesource.com/c/1450902


Reviewed-by: Zhihong Yu <zhihongyu@chromium.org>
Signed-off-by: Vinod Koul <vkoul@kernel.org>
Signed-off-by: Khasim Syed Mohammed <khasim.mohammed@linaro.org>