ARM: dts: am57xx-idk: tpic2810 is on I2C bus, not SPI

commit 50e95b6b ("ARM: dts: am57xx-idk: Add Industrial
output support") added the TPIC2810 device-tree node under
SPI bus instead of I2C1.

Fix it. Tested on AM572x IDK by driving on-board LEDs
connected to TPIC2810

Fixes: 50e95b6b

 ("ARM: dts: am57xx-idk: Add Industrial output support")
Signed-off-by: Sekhar Nori <nsekhar@ti.com>
Acked-by: Andrew F. Davis <afd@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>