wspoon: Update VRM I2C paths for the 5.0 kernel

In the 5.0 Linux kernel, an I2C device path segment changed:
    i2c@1e78a000 -> bus@1e78a000

Signed-off-by: Matt Spinler <spinler@us.ibm.com>
Change-Id: I8d1e9577798c648013b2b4965a364a078bb216e9
diff --git a/meta-witherspoon/recipes-phosphor/chassis/vrm-control/ir35221-unbind-bind.sh b/meta-witherspoon/recipes-phosphor/chassis/vrm-control/ir35221-unbind-bind.sh
index 160cc5d..85d7741 100644
--- a/meta-witherspoon/recipes-phosphor/chassis/vrm-control/ir35221-unbind-bind.sh
+++ b/meta-witherspoon/recipes-phosphor/chassis/vrm-control/ir35221-unbind-bind.sh
@@ -6,7 +6,7 @@
 status=0
 max_retries=3
 driver_path="/sys/bus/i2c/drivers/ir35221/"
-platform_path="/sys/devices/platform/ahb/ahb:apb/ahb:apb:i2c@1e78a000/"
+platform_path="/sys/devices/platform/ahb/ahb:apb/ahb:apb:bus@1e78a000/"
 
 unbind_driver () {
     echo $1 > $driver_path/unbind