[Endless] meson: Hardcode SBAT info

For some reason passing this through debian/rules is not working.

https://phabricator.endlessm.com/T33712
https://phabricator.endlessm.com/T35070

meson_options.txt

@@ -442,17 +442,17 @@ option('dbus', type : 'combo', choices : ['auto', 'true', 'false'],
 
 option('bootloader', type : 'combo', choices : ['auto', 'true', 'false'],
        description : 'sd-boot/stub and userspace tools')
-option('sbat-distro', type : 'string', value : 'auto',
+option('sbat-distro', type : 'string', value : 'endless',
        description : 'SBAT distribution ID, e.g. fedora, or auto for autodetection')
 option('sbat-distro-generation', type : 'integer', value : 1,
        description : 'SBAT distribution generation')
-option('sbat-distro-summary', type : 'string',
+option('sbat-distro-summary', type : 'string', value : 'Endless OS Foundation LLC',
        description : 'SBAT distribution summary, e.g. Fedora')
-option('sbat-distro-pkgname', type : 'string',
+option('sbat-distro-pkgname', type : 'string', value : 'systemd-boot',
        description : 'SBAT distribution package name, e.g. systemd')
 option('sbat-distro-version', type : 'string',
        description : 'SBAT distribution package version, e.g. 248-7.fc34')
-option('sbat-distro-url', type : 'string',
+option('sbat-distro-url', type : 'string', value : 'https://github.com/endlessm/systemd',
        description : 'SBAT distribution URL, e.g. https://src.fedoraproject.org/rpms/systemd')
 option('efi-color-normal', type : 'string', value : 'lightgray,black',
        description : 'general boot loader color in "foreground,background" form, see constants from eficon.h')