serial: samsung: fix spelling mistake

There is a spelling mistake in a comment. Fix it.

Signed-off-by: Tamseel Shams <m.shams@samsung.com>
Reviewed-by: Alim Akhtar <alim.akhtar@samsung.com>
Link: https://lore.kernel.org/r/20200617105907.7143-1-m.shams@samsung.com


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>