[z2300] Add support for XP-Gain disabling

This will maintain compatibility with master, nothing more

Signed-off-by: Schmoozerd <schmoozerd@scriptdev2.com>

(based on commit [12420] - 871161f)

Signed-off-by: Xfurry <xfurry@scriptdev2.com>

(based on commit [s1944] - 6d9a171)

Signed-off-by: Xfurry <xfurry@scriptdev2.com>