video: omap/h3: fix tps65010 dependency

The h3 LCD driver fails to link when tps65010 is configured
as a loadable module:

drivers/built-in.o: In function `h3_panel_disable':
debugfs.c:(.text+0x206ac): undefined reference to `tps65010_set_gpio_out_value'
debugfs.c:(.text+0x206cc): undefined reference to `tps65010_set_gpio_out_value'
drivers/built-in.o: In function `h3_panel_enable':
debugfs.c:(.text+0x206e0): undefined reference to `tps65010_set_gpio_out_value'
debugfs.c:(.text+0x20704): undefined reference to `tps65010_set_gpio_out_value'

This clarifies the dependency so we can only select it if
the dependnecy is built-in.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>