boards: arm: apollo4p_blue_kxr_evb: Move the bt-spi instance to soc dts

Since the pins of bt-spi instance are wired internally in the chip, it will
make sense to move the definition to soc dts so no need for every board
using the chip to redefine the same.

Signed-off-by: Aaron Ye <aye@ambiq.com>
2 files changed