OMAP4: clock: Fix multi-omap boot with reset un-used clocks

This patch uses "ENABLE_ON_INIT" flag on the emif clock nodes
to avoid the emif clk getting cut as part of reset un-used clock
routine which prevents boot.

Since "omap4xxx_clk_init()" calls "clk_enable_init_clocks()"
which increases the usecount on all ENABLE_ON_INIT clocks, it
prevents "omap2_clk_disable_unused()" from disabling the clock.

The real fix is to have driver for EMIF and do clock get/enable
as part of it. The EMIF driver is planned to be done HWMOD way
so till that available to keep omap3_defconfig booting on OMAP4430,
this patch is necessary.
(Will updated the auto-gen script for 44xx accordingly)

The fix was suggested by Paul Walmsley

Signed-off-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Tested-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Paul Walmsley <paul@pwsan.com>