x86: pci: Allow conditionally run VGA rom in S3

Introduce a new CONFIG_S3_VGA_ROM_RUN option so that U-Boot can
bypass executing VGA roms in S3.

Signed-off-by: Bin Meng <bmeng.cn@gmail.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
Tested-by: Stefan Roese <sr@denx.de>

arch/x86/Kconfig

@@ -601,6 +601,18 @@ config HAVE_ACPI_RESUME
 	  is done, U-Boot needs to find out the wakeup vector provided by OSes
 	  and jump there.
 
+config S3_VGA_ROM_RUN
+	bool "Re-run VGA option ROMs on S3 resume"
+	depends on HAVE_ACPI_RESUME
+	default y if HAVE_ACPI_RESUME
+	help
+	  Execute VGA option ROMs in U-Boot when resuming from S3. Normally
+	  this is needed when graphics console is being used in the kernel.
+
+	  Turning it off can reduce some resume time, but be aware that your
+	  graphics console won't work without VGA options ROMs. Set it to N
+	  if your kernel is only on a serial console.
+
 config STACK_SIZE
 	hex
 	depends on HAVE_ACPI_RESUME