media: vsp1: Reword uses of 'fragment' as 'body'

Throughout the codebase, the term 'fragment' is used to represent a
display list body. This term duplicates the 'body' which is already in
use.

The datasheet references these objects as a body, therefore replace all
mentions of a fragment with a body, along with the corresponding
pluralised terms.

Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart+renesas@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>