bsps/shared/acpi: Use vprintk for AcpiOsPrintf

AcpiOsPrintf() and AcpiOsVprintf() used vprintf(), which relies on
standard I/O and newlib reentrancy structures.

When acpi_tables_initialize() is called from bsp_start(), the system
has not completed initialization and no thread is executing yet.
Calling vprintf() at this stage attempts to read libc_reent via a null
pointer, which on x86_64 targets causes a triple fault crash during boot.

Use vprintk() from <rtems/bspIo.h> instead of vprintf() to route ACPICA
OSL output through the early polled kernel character device.

Fixes #5751.

bsps/shared/acpi/osl/osl_output.c

@@ -27,18 +27,18 @@
 
 #include <acpi/acpica/acpi.h>
 
-#include <stdio.h>
+#include <rtems/bspIo.h>
 
 void AcpiOsPrintf(const char* Format, ...)
 {
   va_list ap;
 
   va_start(ap, Format);
-  vprintf(Format, ap);
+  vprintk(Format, ap);
   va_end(ap);
 }
 
 void AcpiOsVprintf(const char* Format, va_list Args)
 {
-  vprintf(Format, Args);
+  vprintk(Format, Args);
 }