[libcamera-devel] Introduce -Wextra-semi to libcamera

[Hirokazu Honda]

I introduce -Wextra-semi compiler option in this patch series.
The compiler option is currently available with clang.
It enables a developer to get warning if the code contains
unnecessary semicolons. It should help our future development.
Before I add the option to meson.build, I remove existing
unnecessary semicolons when libcamera is built with
-Dandroid=enabled.