kernel: Set GCC version to 80300 by default

The kernel 4.19 configuration contains the GCC version used, set it to
8.3.0 as this is now our default compiler.

Signed-off-by: Hauke Mehrtens <[email protected]>

target/linux/generic/config-4.19

@@ -1604,7 +1604,7 @@ CONFIG_GACT_PROB=y
 # CONFIG_GAMEPORT is not set
 # CONFIG_GATEWORKS_GW16083 is not set
 # CONFIG_GCC_PLUGINS is not set
-CONFIG_GCC_VERSION=70400
+CONFIG_GCC_VERSION=80300
 # CONFIG_GCOV is not set
 # CONFIG_GCOV_KERNEL is not set
 # CONFIG_GDB_SCRIPTS is not set