arm64: dts: ti: k3-am69-aquila: Change main_spi0/2 CS to GPIO mode

arm64: dts: ti: k3-am69-aquila: Change main_spi0/2 CS to GPIO mode

Hardware chip select does not work correctly on main_spi0 and
main_spi2 controllers. Testing shows main_spi2 loses CS state
during runtime PM suspend, while main_spi0 cannot drive CS HIGH
when bus is idle.

Use GPIO-based chip select for both controllers.

Fixes: 39ac6623b1d8 ("arm64: dts: ti: Add Aquila AM69 Support")
Cc: stable@vger.kernel.org
Signed-off-by: Vitor Soares <vitor.soares@toradex.com>
Reviewed-by: Francesco Dolcini <francesco.dolcini@toradex.com>
Link: https://patch.msgid.link/20260112175350.79270-2-ivitro@gmail.com
Signed-off-by: Nishanth Menon <nm@ti.com>