meson: remove meson option 'use-json'

In a previous change, support for yaml configuration was removed. Remove
the leftover meson option which is unused now.

Tested: clean build succeeds

Fixes: 89caaaf07603 ("meson: remove yaml configuration")
Change-Id: I2701345d99c2a8d4b3c5a9326f5ae45d2fe01962
Signed-off-by: Alexander Hansen <alexander.hansen@9elements.com>