vc/amd/opensil/genoa_poc/opensil_console: fix host debug print function

Since we pass va_list list to the print function, we need to use vprintk
instead of printk. Earlier versions of this code used vsnprintf and a
local buffer, but when that code was reworked to not need the temporary
buffer, it was replaced by printk instead of the correct vprintk.

TEST=Now the console output from openSIL looks as expected:

Example line from openSIL's console output when it prints the MPIO
configuration from a log some commits before this patch:

  Host PCI Address - -1352681400:-1353251983:7

Same line with this patch applied looks how it's supposed to:

  Host PCI Address - 0:0:0

Signed-off-by: Felix Held <felix-coreboot@felixheld.de>
Tested-by: Varshit Pandya <pandyavarshit@gmail.com>
Change-Id: Ia931cc80dea5b7eabb75cfb19f8baa9a09cd2dbf
Reviewed-on: https://review.coreboot.org/c/coreboot/+/80203
Reviewed-by: Matt DeVillier <matt.devillier@amd.corp-partner.google.com>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-by: Varshit Pandya <pandyavarshit@gmail.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/vendorcode/amd/opensil/genoa_poc/opensil_console.c

@@ -39,6 +39,6 @@ void HostDebugService(size_t MsgLevel, const char *SilPrefix, const char *Messag
 	/* print formatted message */
 	va_list args;
 	va_start(args, Line);
-	printk(loglevel, Message, args);
+	vprintk(loglevel, Message, args);
 	va_end(args);
 }