mb/google/ocelot: Add option to enable VGA mode 12

This commit adds a new Kconfig option to the ocelot mainboard
to enable VGA mode 12 support for early Sign of Life (eSOL).

- This option, `OCELOT_VGA_MODE12_SUPPORT`, is dependent on
  `FSP_UGOP_EARLY_SIGN_OF_LIFE`.
- It selects `ROMSTAGE_VGA` and `FSP_VGA_MODE12` to enable the
  necessary VGA components.

BUG=None
TEST=Verify VGA text rotation on ocelot RVP.

Change-Id: I71dff6e58c3e4487079c0090848ecde9da5153d7
Signed-off-by: Avi Uday <aviuday@google.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/90731
Reviewed-by: Kapil Porwal <kapilporwal@google.com>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/mainboard/google/ocelot/Kconfig

@@ -227,4 +227,13 @@ config OVERRIDE_DEVICETREE
 config VBOOT
 	select VBOOT_LID_SWITCH
 
+config OCELOT_VGA_MODE12_SUPPORT
+	bool "Enable VGA Mode 12 support for eSOL"
+	default n
+	depends on FSP_UGOP_EARLY_SIGN_OF_LIFE
+	select ROMSTAGE_VGA
+	select FSP_VGA_MODE12
+	help
+	  Select this if the FSP supports VGA mode 12 for eSOL.
+
 endif # BOARD_GOOGLE_OCELOT_COMMON