MIPS: ralink: Fix incorrect assignment on ralink_soc

[ Upstream commit 08d90c81b714482dceb5323d14f6617bcf55ee61 ]

ralink_soc sould be assigned to RT3883_SOC, replace incorrect
comparision with assignment.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Fixes: 418d29c ("MIPS: ralink: Unify SoC id handling")
Cc: John Crispin <john@phrozen.org>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/14903/
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
Signed-off-by: Sasha Levin <alexander.levin@verizon.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

Author: Colin Ian King

arch/mips/ralink/rt3883.c

@@ -144,5 +144,5 @@ void prom_soc_init(struct ralink_soc_info *soc_info)
 
 	rt2880_pinmux_data = rt3883_pinmux_data;
 
-	ralink_soc == RT3883_SOC;
+	ralink_soc = RT3883_SOC;
 }