mb/intel/tglrvp/Kconfig: Drop unnecessary choice name

The only reason to use a named choice statement is if you plan on
having the choice statement in multiple places. Since the `TGL_EC`
name is not used anywhere else, we might as well get rid of it.

Change-Id: Ic0bddefd007ef961bbff61fd656475cae78148e2
Signed-off-by: Angel Pons <th3fanbus@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/43836
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Tim Wawrzynczak <twawrzynczak@chromium.org>

src/mainboard/intel/tglrvp/Kconfig

@@ -77,7 +77,7 @@ config DIMM_SPD_SIZE
 	int
 	default 512
 
-choice TGL_EC
+choice
 	prompt "ON BOARD EC"
 	default TGL_CHROME_EC
 	help