doc: samsung: Mention enabled eMMC in E850-96 board doc

eMMC is enabled on E850-96 board now. Mention that in the board
documentation.

Signed-off-by: Sam Protsenko <semen.protsenko@linaro.org>
Signed-off-by: Minkyu Kang <mk7.kang@samsung.com>
1 file changed