rtc: at91/Kconfig: remove useless options
rtc: at91/Kconfig: remove useless options

As we removed all the !DT boards during 3.19 cycle, we can now remove these
options.

Reported-by: Paul Bolle <0bda9a89324ffe2d19adec61a9f1cd9f8c8e45f0@tiscali.nl>
Signed-off-by: Nicolas Ferre <45b517be0e5ec6dc3a39715767c1d18e090d39b4@atmel.com>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs