zephyr: add missing binding for the rt9490 emulator
zephyr: add missing binding for the rt9490 emulator

The RT9490 emulator was missing the binding file what caused the
DT_HAS_ macro not being defined in the .config file.

BUG=b:251812799
BRANCH=main
TEST=build fw and check that macro is defined properly

Change-Id: I1c1e84bafb57ae9803c70c82e1c34faee0f6218c
Signed-off-by: Michał Barnaś <77666125932addc6fc525b281b518fd8fd2203d8@semihalf.com>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/3982639
Reviewed-by: Keith Short <f6d578f97033c25f1206cb57d52f358974c82954@chromium.org>

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