ARM: imx: pcm037: make pcm970_sja1000_platform_data static

Fix sparse warning:

arch/arm/mach-imx/mach-pcm037.c:407:30: warning: symbol
'pcm970_sja1000_platform_data' was not declared. Should it be static?
Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Ma Feng <mafeng.ma@huawei.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm/mach-imx/mach-pcm037.c

@@ -404,7 +404,7 @@ static struct resource pcm970_sja1000_resources[] = {
 	},
 };
 
-struct sja1000_platform_data pcm970_sja1000_platform_data = {
+static struct sja1000_platform_data pcm970_sja1000_platform_data = {
 	.osc_freq	= 16000000,
 	.ocr		= OCR_TX1_PULLDOWN | OCR_TX0_PUSHPULL,
 	.cdr		= CDR_CBP,