src/drivers: Drop unneeded empty lines

Change-Id: I202e5d285612b9bf237b588ea3c006187623fdc3
Signed-off-by: Elyes HAOUAS <ehaouas@noos.fr>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/44609
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Michael Niewöhner <foss@mniewoehner.de>

src/drivers/generic/cbfs-serial/cbfs-serial.c

@@ -5,7 +5,6 @@
 #include <smbios.h>
 #include <string.h>
 
-
 #define MAX_SERIAL_LENGTH 0x100
 
 const char *smbios_mainboard_serial_number(void)