soc/amd/common/block/smbus: remove stale comment

The comment doesn't apply to Stoneyridge, Picasso and Cezanne which are
the only SoCs selecting SOC_AMD_COMMON_BLOCK_SMBUS.

Signed-off-by: Felix Held <felix-coreboot@felixheld.de>
Change-Id: I9024de9d3731a0bc64365f959142bf657a53e193
Reviewed-on: https://review.coreboot.org/c/coreboot/+/49908
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Martin Roth <martinroth@google.com>

src/soc/amd/common/block/smbus/sm.c

@@ -9,11 +9,6 @@
 #include <arch/ioapic.h>
 #include <soc/southbridge.h>
 
-/*
-* The southbridge enables all USB controllers by default in SMBUS Control.
-* The southbridge enables SATA by default in SMBUS Control.
-*/
-
 static void sm_init(struct device *dev)
 {
 	setup_ioapic(VIO_APIC_VADDR, CONFIG_MAX_CPUS);