{soc/amd,sb/amd/hudson}: Fix generating the ACPI mcfg

The last argument for acpi_fill_mcfg() is the last PCI bus, which is
an uint8_t, not the total number of busses, which overflows the
argument if CONFIG_MMCONF_BUS_NUMBER is 256.

Change-Id: I8887e14128dbe54688eb6e803d6694b7c29956c1
Signed-off-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/35872
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-by: Marshall Dawson <marshalldawson3rd@gmail.com>
Reviewed-by: Michał Żygowski <michal.zygowski@3mdeb.com>

src/soc/amd/stoneyridge/northbridge.c

@@ -170,7 +170,7 @@ unsigned long acpi_fill_mcfg(unsigned long current)
 					     CONFIG_MMCONF_BASE_ADDRESS,
 					     0,
 					     0,
-					     CONFIG_MMCONF_BUS_NUMBER);
+					     CONFIG_MMCONF_BUS_NUMBER - 1);
 
 	return current;
 }

src/southbridge/amd/pi/hudson/lpc.c

@@ -324,7 +324,7 @@ unsigned long acpi_fill_mcfg(unsigned long current)
 					     CONFIG_MMCONF_BASE_ADDRESS,
 					     0,
 					     0,
-					     CONFIG_MMCONF_BUS_NUMBER);
+					     CONFIG_MMCONF_BUS_NUMBER - 1);
 	return current;
 }