staging: r8188eu: DYNAMIC_BB_DYNAMIC_TXPWR is not used

Remove the DYNAMIC_BB_DYNAMIC_TXPWR capability. It is cleared but not used.

DYNAMIC_BB_DYNAMIC_TXPWR defines a bit in podmpriv->SupportAbility that's
set or cleared. There's no code that checks this bit explicitly.

There's also no code that makes a copy of SupportAbility and checks the
DYNAMIC_BB_DYNAMIC_TXPWR in the copy. SupportAbility is copied to
podmpriv->BK_SupportAbility. The only use of BK_SupportAbility is to
restore a previously saved value. The other remaining reader of
SupportAbility is a private debug ioctl.

It's safe to assume that DYNAMIC_BB_DYNAMIC_TXPWR is not used, not even
indirectly.

Signed-off-by: Martin Kaiser <martin@kaiser.cx>
Link: https://lore.kernel.org/r/20220321203031.143486-4-martin@kaiser.cx


Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>