Adding the dependency seems like a more reasonable thing compared to
ifdef-ing the bits, as if one has an XO-1.75 they almost certainly want
a baterry and AC adapter support.
Reported-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Lubomir Rintel <lkundrak@v3.sk> Acked-by: Randy Dunlap <rdunlap@infradead.org> Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>