ARM: OMAP AM33xx: hwmod data: resolve sparse warnings

Commit 70384a6a ("ARM: OMAP3+:
hwmod: Add AM33XX HWMOD data for davinci_mdio module") adds two
new sparse warnings:

arch/arm/mach-omap2/omap_hwmod_33xx_data.c:2518:30: warning: symbol 'am33xx_mdio_addr_space' was not declared. Should it be static?
arch/arm/mach-omap2/omap_hwmod_33xx_data.c:2526:26: warning: symbol 'am33xx_cpgmac0__mdio' was not declared. Should it be static?

Fix by marking the two new records as static.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Mugunthan V N <mugunthanvnm@ti.com>
Cc: Vaibhav Hiremath <hvaibhav@ti.com>
Cc: Peter Korsgaard <jacmet@sunsite.dk>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: David S. Miller <davem@davemloft.net>
Acked-by: Mugunthan V N <mugunthanvnm@ti.com>