staging: olpc_dcon: allow simultaneous XO-1 and XO-1.5 support

This patch remove model related configuration.
Since the module can decide which platform data to use itself base on
current running olpc board.

Also change module dependency from (GPIO_CS5535 || GPIO_CS5535=n)
to (GPIO_CS5535 || ACPI) because original one does not make any sense
and module only doing real work when GPIO_CS5535 or ACPI is setted.

Remove kernel configurations:
- FB_OLPC_DCON_1
- FB_OLPC_DCON_1_5

Signed-off-by: Jerry Lin <wahahab11@gmail.com>
Link: https://lore.kernel.org/r/20190906010613.GA562@compute1
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>