dm: treewide: Rename 'platdata' variables to just 'plat'

We use 'priv' for private data but often use 'platdata' for platform data.
We can't really use 'pdata' since that is ambiguous (it could mean private
or platform data).

Rename some of the latter variables to end with 'plat' for consistency.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/adc/sandbox.c b/drivers/adc/sandbox.c
index 14f2c2a..905ce4f 100644
--- a/drivers/adc/sandbox.c
+++ b/drivers/adc/sandbox.c
@@ -137,7 +137,7 @@
 
 int sandbox_adc_ofdata_to_platdata(struct udevice *dev)
 {
-	struct adc_uclass_platdata *uc_pdata = dev_get_uclass_platdata(dev);
+	struct adc_uclass_plat *uc_pdata = dev_get_uclass_plat(dev);
 
 	uc_pdata->data_mask = SANDBOX_ADC_DATA_MASK;
 	uc_pdata->data_format = ADC_DATA_FORMAT_BIN;