payloads/external/Makefile.inc: Pass hardware IRQ option to SeaBIOS Makefile

The hardware IRQ option was not passed to SeaBIOS Makefile and resulted
in HARDWARE_IRQ being permanently disabled regardless of Kconfig
selection in coreboot. On platforms that need the hardware IRQ it caused
hangs at boot menu or iPXE prompts.

TEST=enter SeaBIOS boot menu on Libretrend LT1000
Signed-off-by: Michał Żygowski <michal.zygowski@3mdeb.com>
Change-Id: Iafcfd743177bbcd1ee23e227c74dd8268c4c23c6
Reviewed-on: https://review.coreboot.org/c/coreboot/+/41147

Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Matt DeVillier <matt.devillier@gmail.com>
Reviewed-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-by: Nico Huber <nico.h@gmx.de>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>

payloads/external/Makefile.inc

@@ -102,7 +102,8 @@ payloads/external/SeaBIOS/seabios/out/bios.bin.elf: $(DOTCONFIG)
 			CONFIG_SEABIOS_DEBUG_LEVEL=$(CONFIG_SEABIOS_DEBUG_LEVEL) \
 			CONFIG_DRIVERS_UART_8250MEM_32=$(CONFIG_DRIVERS_UART_8250MEM_32) \
 			CONFIG_ENABLE_HSUART=$(CONFIG_ENABLE_HSUART) \
-			CONFIG_CONSOLE_UART_BASE_ADDRESS=$(CONFIG_CONSOLE_UART_BASE_ADDRESS)
+			CONFIG_CONSOLE_UART_BASE_ADDRESS=$(CONFIG_CONSOLE_UART_BASE_ADDRESS) \
+			CONFIG_SEABIOS_HARDWARE_IRQ=$(CONFIG_SEABIOS_HARDWARE_IRQ)
 
 payloads/external/SeaBIOS/seabios/out/vgabios.bin: payloads/external/SeaBIOS/seabios/out/bios.bin.elf
 payloads/external/SeaBIOS/seabios/.config: payloads/external/SeaBIOS/seabios/out/bios.bin.elf