src: capitalize 'RAM'

Change-Id: Ia05cb2de1b9f2a36fc9ecc22fb82f0c14da00a76
Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/39029
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Angel Pons <th3fanbus@gmail.com>

src/cpu/intel/microcode/Kconfig

@@ -4,4 +4,4 @@ config MICROCODE_UPDATE_PRE_RAM
 	default y
 	help
 	  Select this option if you want to update the microcode
-	  during the cache as ram setup.
+	  during the cache as RAM setup.