a) lcd_enabled() is now lcd_active(), and is available for HAVE_LCD_SLEEP only targets (e.g. ipod video) too. It was depandent on HAVE_LCD_ENALE only before
b) rename the hook accordingly, and implement the hook for other other targets too (e.g. the clip [the only mono target with lcd_enable/lcd_sleep yet, so the code is still in the lcd driver], ipod, fuze, c200)
git-svn-id: svn://svn.rockbox.org/rockbox/trunk@20331 a1c6a512-1295-4272-9138-f99709370657
