riscv: defconfig: enable gpio support for TH1520

Enable gpio-dwapb driver which is used by TH1520-based boards like the
BeagleV Ahead and the Sipeed LicheePi 4A.

Signed-off-by: Drew Fustini <drew@pdp7.com>
Link: https://lore.kernel.org/r/20241014205315.1349391-1-drew@pdp7.com


Signed-off-by: Palmer Dabbelt <palmer@rivosinc.com>