build: Fix multiline string warning
build: Fix multiline string warning

meson expects multiline strings to use different quoting syntax.

Change-Id: I9282587b67e55602f6118710b4568c1993e957f0
Signed-off-by: William A. Kennington III <30fff5198f4d10ca1117e5f3ec82f3b4b8900d81@google.com>

openbmc/stdplus,openbmc/stdplus