sunxi: f1c100s: re-enable SYSRESET

The SoC .dtsi originally submitted for the Allwinner F1C100s had the
wrong compatible string for the watchdog, which broke U-Boot's reset
functionality. To quickly fix this, we disable CONFIG_SYSRESET in
cfcf1952 ("sunxi: f1c100s: Drop SYSRESET to enable reset
functionality"), so that U-Boot's hardcoded reset driver could take over.

After this was properly fixed in the devicetree, we reverted that patch
in 92373de0 ("Revert "sunxi: f1c100s: Drop SYSRESET to enable reset
functionality"), however this line sneaked back in with d0ee7f29
("Convert CONFIG_SYS_PBSIZE to Kconfig"), so during a Kconfig update.

Remove this line (again), to use the proper reset driver.

Fixes: d0ee7f29 ("Convert CONFIG_SYS_PBSIZE to Kconfig")
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Samuel Holland <samuel@sholland.org>