media: hantro: Fix overfill bottom register field name
The Hantro H1 hardware can crop off pixels from the right and bottom of
the source frame. These are controlled with the H1_REG_IN_IMG_CTRL_OVRFLB
and H1_REG_IN_IMG_CTRL_OVRFLR in the H1_REG_IN_IMG_CTRL register.
The ChromeOS kernel driver that this was based on incorrectly added the
_D4 suffix H1_REG_IN_IMG_CTRL_OVRFLB. This field crops the bottom of the
input frame, and the number is _not_ divided by 4. [1]
Correct the name to avoid confusion when crop support with the selection
API is added.