ARM: OMAP2xxx: clock: move virt_prcm_set code into clkt2xxx_virt_prcm_set.c

Collect all of the virt_prcm_set-specific clocktype code into
mach-omap2/clkt2xxx_virt_prcm_set.c.  Remove its dependency on the
'sclk' and 'vclk' global variables.  Those variables will be removed
by subsequent patches.

This is part of the process of cleaning up the OMAP2xxx clock code
and preparing for the removal of the omap_prcm_restart() function.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Tested-by: Vaibhav Hiremath <hvaibhav@ti.com>

arch/arm/mach-omap2/clock2xxx.h

@@ -20,6 +20,8 @@ u32 omap2xxx_get_apll_clkin(void);
 u32 omap2xxx_get_sysclkdiv(void);
 void omap2xxx_clk_prepare_for_reboot(void);
 void omap2xxx_clkt_dpllcore_init(struct clk *clk);
+void omap2xxx_clkt_vps_check_bootloader_rates(void);
+void omap2xxx_clkt_vps_late_init(void);
 
 #ifdef CONFIG_SOC_OMAP2420
 int omap2420_clk_init(void);