[Blackfin] arch: Fix bug - Setting peripheral_map only when dma channel is UART2/3.

Singed-off-by: Sonic Zhang <sonic.zhang@analog.com>
Signed-off-by: Bryan Wu <cooloney@kernel.org>

arch/blackfin/kernel/bfin_dma_5xx.c

@@ -105,13 +105,14 @@ int request_dma(unsigned int channel, char *device_id)
 	mutex_unlock(&(dma_ch[channel].dmalock));
 
 #ifdef CONFIG_BF54x
-	if (channel >= CH_UART2_RX && channel <= CH_UART3_TX &&
-		strncmp(device_id, "BFIN_UART", 9) == 0)
+	if (channel >= CH_UART2_RX && channel <= CH_UART3_TX) {
+		if (strncmp(device_id, "BFIN_UART", 9) == 0)
 			dma_ch[channel].regs->peripheral_map |=
 				(channel - CH_UART2_RX + 0xC);
 		else
 			dma_ch[channel].regs->peripheral_map |=
 				(channel - CH_UART2_RX + 0x6);
+	}
 #endif
 
 	dma_ch[channel].device_id = device_id;