package/perl-device-serialport: fix LICENSE variable

A bad copy/paste lead to the LICENSE variable using the wrong
prefix. Thanks to check-package, this was detected, and is now fixed
by this commit.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

package/perl-device-serialport/perl-device-serialport.mk

@@ -7,7 +7,7 @@
 PERL_DEVICE_SERIALPORT_VERSION = 1.04
 PERL_DEVICE_SERIALPORT_SOURCE = Device-SerialPort-$(PERL_DEVICE_SERIALPORT_VERSION).tar.gz
 PERL_DEVICE_SERIALPORT_SITE = $(BR2_CPAN_MIRROR)/authors/id/C/CO/COOK
-PERL_DBI_LICENSE = Artistic or GPL-1.0+
+PERL_DEVICE_SERIALPORT_LICENSE = Artistic or GPL-1.0+
 PERL_DEVICE_SERIALPORT_LICENSE_FILES = README
 
 $(eval $(perl-package))