zephyr: ite: Use EC_SPI_RX_READY macro
zephyr: ite: Use EC_SPI_RX_READY macro

Using EC_SPI_RX_READY instead of EC_SPI_OLD_READY
prevents the SDO line going high when the AP shuts down.

BUG=b:216831450
BRANCH=none
TEST=zmake testall
     Verified on scope that SHI_SDO does not pulse high
     during AP Shutdown

Signed-off-by: Sam Hurst <500b4cddcd66abe3fe333e92c4c95d7f41e62e4e@google.com>
Change-Id: I0ac0eeb26fdb558cfb6c9fc0dbfe61240e2195ff
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3674596
Reviewed-by: Wai-Hong Tam <04b587fdf5845741a0c5a8b9cd59ca72d73ef8fc@google.com>

coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec