ARM: OMAP4: HWMOD: fix DSS clock data

The OMAP4 HWMOD data currently contains errors with DSS clocks:

dss_hdmi and dss_venc have their main_clks wrong. The clocks should be
dss_48mhz_clk and dss_tv_clk, respectively.

These problems were temporarily fixed with the DSS patches
9ede365a ("HACK: OMAP: DSS2: clk hack
for OMAP2/3"), and df5d3ed2 ("OMAP:
DSS2: HDMI: fix hdmi clock name"), which can be reverted after this
patch.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
Signed-off-by: Paul Walmsley <paul@pwsan.com>