powerpc: mpc8xx: remove some of tqm8xx board family without maintainers

Remove NSCU, TK885D, TQM823M, TQM850M, TQM855M, TQM860M,
TQM862L, TQM826M, TQM866M, TQM885D boards support.

These boards are old enough and have no maintainers.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
Cc: Wolfgang Denk <wd@denx.de>
Series-to: uboot
Commit-notes:

I built all the other boards and compared MD5SUM.

I confirmed this patch has no impact against them.

END
mpc8260: remove ppmc8260 board support
powerpc: mpc824x: remove MUSENKI and Sandpoint8245 board support

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
powerpc: mpc8xx: remove stxxtc board support

Because this is the last board defining CONFIG_MPC885_FAMILY,
drivers/usb/gadget/mpc8xx_udc.c has also been dropped.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
powerpc: mpc8xx: remove svm_sc8xx board
powerpc: mpc8xx: remove SXNI855T board support

Because this is the last board definint CONFIG_RTC_DS1306,
drivers/rtc/ds1306.c has also been removed.

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
powerpc: mpc8xx: remove GEN860T, GEN806T_SC board support

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
powerpc: mpc8xx: remove FLAGADM board support

Signed-off-by: Masahiro Yamada <yamada.m@jp.panasonic.com>
powerpc: mpc8260: remove sacsng board support
powerpc: mpc8260: remove ep8260 board support