Fix spacings in meson_options

The meson_options.txt looks to be very cumbersome and is difficult to
read & maintain due to in-consistent white spacing, and the lines are
longer than 80 characters.

This commit would fix those by migrating the syntax to new lines for
each option key, also warps the comments and the description to
80 characters & uses multilines for descriptions that are larger than 80
characters.Doing this should make this file more maintainable in future.

Change-Id: Ic8421cc21b8809c659be8e63b02b6877542a47fd
Signed-off-by: Manojkiran Eda <manojkiran.eda@gmail.com>