OMAP2xxx clock: move sys_clk code into mach-omap2/clkt2xxx_sys.c

Move the sys_clk clock functions from clock2xxx.c to
mach-omap2/clkt2xxx_sys.c.  This is intended to make the clock code
easier to understand, since all of the functions needed to manage the
sys_clk are now located in their own file, rather than being mixed
with other, unrelated functions.

Clock debugging is also now more finely-grained, since the DEBUG
macro can now be defined for the sys_clk clock alone.  This
should reduce unnecessary console noise when debugging.

Also, if at some future point the mach-omap2/ directory is split into
OMAP2/3/4 variants, this clkt file can be placed in the mach-omap2xxx/
directory, rather than shared with other chip types that don't use
this clock type.

Thanks to Alexander Shishkin <virtuoso@slind.org> for his comments to
improve the patch description.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Alexander Shishkin <virtuoso@slind.org>

arch/arm/mach-omap2/clock2xxx.h

@@ -11,9 +11,8 @@
 unsigned long omap2_table_mpu_recalc(struct clk *clk);
 int omap2_select_table_rate(struct clk *clk, unsigned long rate);
 long omap2_round_to_table_rate(struct clk *clk, unsigned long rate);
-unsigned long omap2_sys_clk_recalc(struct clk *clk);
+unsigned long omap2xxx_sys_clk_recalc(struct clk *clk);
 unsigned long omap2_osc_clk_recalc(struct clk *clk);
-unsigned long omap2_sys_clk_recalc(struct clk *clk);
 unsigned long omap2_dpllcore_recalc(struct clk *clk);
 int omap2_reprogram_dpllcore(struct clk *clk, unsigned long rate);
 unsigned long omap2xxx_clk_get_core_rate(struct clk *clk);