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 <pebolle@tiscali.nl>
Signed-off-by: Nicolas Ferre <nicolas.ferre@atmel.com>

drivers/rtc/Kconfig

@@ -1141,34 +1141,6 @@ config RTC_DRV_AT91SAM9
 	  probably want to use the real RTC block instead of the "RTT as an
 	  RTC" driver.
 
-config RTC_DRV_AT91SAM9_RTT
-	int
-	range 0 1
-	default 0
-	depends on RTC_DRV_AT91SAM9
-	help
-	  This option is only relevant for legacy board support and
-	  won't be used when booting a DT board.
-
-	  More than one RTT module is available. You can choose which
-	  one will be used as an RTC. The default of zero is normally
-	  OK to use, though some systems use that for non-RTC purposes.
-
-config RTC_DRV_AT91SAM9_GPBR
-	int
-	range 0 3
-	default 0
-	prompt "Backup Register Number"
-	depends on RTC_DRV_AT91SAM9
-	help
-	  This option is only relevant for legacy board support and
-	  won't be used when booting a DT board.
-
-	  The RTC driver needs to use one of the General Purpose Backup
-	  Registers (GPBRs) as well as the RTT. You can choose which one
-	  will be used. The default of zero is normally OK to use, but
-	  on some systems other software needs to use that register.
-
 config RTC_DRV_AU1XXX
 	tristate "Au1xxx Counter0 RTC support"
 	depends on MIPS_ALCHEMY