rt2x00: add support for RT5350 WiSoC

Support for the RT5350 WiSoC was added to OpenWrt after having a
lengthy debate about the legality of the original submission, see
https://lists.openwrt.org/pipermail/openwrt-devel/2013-January/018224.html
MTK/Ralink Acked replied and says we can merge this patch under the GPL.
https://dev.openwrt.org/changeset/36177

Signed-off-by: Serge Vasilugin <vasilugin@yandex.ru>
Tested-by: Michel Stempin <michel.stempin@wanadoo.fr>
Acked-by: John Crispin <blogic@openwrt.org>
[daniel@makrotopia.org: added commit message, cleaned up code]
Signed-off-by: Daniel Golle <daniel@makrotopia.org>
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>

drivers/net/wireless/ralink/rt2x00/rt2x00.h

@@ -170,6 +170,7 @@ struct rt2x00_chip {
 #define RT3572		0x3572
 #define RT3593		0x3593
 #define RT3883		0x3883	/* WSOC */
+#define RT5350		0x5350  /* WSOC 2.4GHz */
 #define RT5390		0x5390  /* 2.4GHz */
 #define RT5392		0x5392  /* 2.4GHz */
 #define RT5592		0x5592