[ARM] OMAP: Fix sparse, checkpatch warnings in OMAP2/3 PRCM/PM code

Fix sparse & checkpatch warnings in OMAP2/3 PRCM & PM code.  This mostly
consists of:

- converting pointer comparisons to integers in form similar to
  (ptr == 0) to the standard idiom (!ptr)

- labeling a few non-static private functions as static

- adding prototypes for *_init() functions in the appropriate header
  files, and getting rid of the corresponding open-coded extern
  prototypes in other C files

- renaming the variable 'sclk' in mach-omap2/clock.c:omap2_get_apll_clkin
  to avoid shadowing an earlier declaration

Clean up checkpatch issues.  This mostly involves:

- converting some asm/ includes to linux/ includes

- cleaning up some whitespace

- getting rid of braces for conditionals with single following statements

Also take care of a few odds and ends, including:

- getting rid of unlikely() and likely() - none of this code is particularly
  fast-path code, so the performance impact seems slim; and some of those
  likely() and unlikely() indicators are probably not as accurate as the
  ARM's branch predictor

- removing some superfluous casts

linux-omap source commit is 347df59f5d20fdf905afbc26b1328b0e28a8a01b.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>

arch/arm/mach-omap2/clock.h

@@ -27,7 +27,7 @@ void omap2_clk_disable(struct clk *clk);
 long omap2_clk_round_rate(struct clk *clk, unsigned long rate);
 int omap2_clk_set_rate(struct clk *clk, unsigned long rate);
 int omap2_clk_set_parent(struct clk *clk, struct clk *new_parent);
-int omap2_dpll_rate_tolerance_set(struct clk *clk, unsigned int tolerance);
+int omap2_dpll_set_rate_tolerance(struct clk *clk, unsigned int tolerance);
 long omap2_dpll_round_rate(struct clk *clk, unsigned long target_rate);
 
 #ifdef CONFIG_OMAP_RESET_CLOCKS