MIPS: Fix build with DEBUG_ZBOOT and MACH_JZ4780

MIPS: Fix build with DEBUG_ZBOOT and MACH_JZ4780

Ingenic SoC declares ZBOOT support, but debug definitions are missing
for MACH_JZ4780 resulting in a build failure when DEBUG_ZBOOT is set.
The UART addresses are same as with JZ4740, so fix by covering JZ4780
with those as well.

Signed-off-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/12830/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>