Kernel has error message(Beagle Board)

I use Keneral(omap3_beagle_defconfig) & CROSS_COMPILE 4.3.2 to make
uImage

my system is (window + VM), it runs ubuntu 10.04 version
below is my error message , please help me

==>
drivers/built-in.o: In function `rtc_alarm_remove_device':
staging.c:(.text+0xe9f8c): undefined reference to `rtc_irq_unregister'
drivers/built-in.o: In function `rtc_alarm_add_device':
staging.c:(.text+0xea004): undefined reference to `rtc_irq_register'
drivers/built-in.o: In function `alarm_resume':
staging.c:(.text+0xea288): undefined reference to `rtc_set_alarm'
drivers/built-in.o: In function `alarm_suspend':
staging.c:(.text+0xea3e4): undefined reference to `rtc_read_time'
staging.c:(.text+0xea44c): undefined reference to `rtc_set_alarm'
staging.c:(.text+0xea458): undefined reference to `rtc_read_time'
staging.c:(.text+0xea4e0): undefined reference to `rtc_set_alarm'
drivers/built-in.o: In function `alarm_set_rtc':
staging.c:(.text+0xeac28): undefined reference to `rtc_set_time'
drivers/built-in.o: In function `alarm_driver_init':
staging.c:(.init.text+0x73c8): undefined reference to `rtc_class'
make: *** [.tmp_vmlinux1] Error 1
==>

which version of kernel you are using?