MIPS: No need to select ARCH_SUPPORTS_MSI

Commit c24a8a7a ("MIPS: Netlogic: Add MSI support for XLP") added
"select ARCH_SUPPORTS_MSI". But the Kconfig symbol ARCH_SUPPORTS_MSI was
already removed in v3.12, so that select is a nop. Drop it.
Signed-off-by: Paul Bolle <pebolle@tiscali.nl>
Cc: Jayachandran C <jchandra@broadcom.com>
Cc: John Crispin <blogic@openwrt.org>
Cc: linux-mips@linux-mips.org
Cc: linux-kernel@vger.kernel.org
Patchwork: https://patchwork.linux-mips.org/patch/6521/Signed-off-by: Ralf Baechle <ralf@linux-mips.org>

arch/mips/Kconfig

@@ -785,7 +785,6 @@ config NLM_XLP_BOARD
 	select CEVT_R4K
 	select CSRC_R4K
 	select IRQ_CPU
-	select ARCH_SUPPORTS_MSI
 	select ZONE_DMA32 if 64BIT
 	select SYNC_R4K
 	select SYS_HAS_EARLY_PRINTK