cpuimx27: fix compile when ULPI is selected

without this patch we get :
arch/arm/mach-imx/built-in.o: In function `eukrea_cpuimx27_init':
eukrea_mbimx27-baseboard.c:(.init.text+0x44c): undefined reference to `mxc_ulpi_access_ops'

Signed-off-by: Eric Bénard <eric@eukrea.com>
Signed-off-by: Sascha Hauer <s.hauer@pengutronix.de>