[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>
diff --git a/arch/arm/plat-omap/include/mach/powerdomain.h b/arch/arm/plat-omap/include/mach/powerdomain.h
index 2806a9c..4948cb7 100644
--- a/arch/arm/plat-omap/include/mach/powerdomain.h
+++ b/arch/arm/plat-omap/include/mach/powerdomain.h
@@ -145,6 +145,7 @@
 
 int pwrdm_set_next_pwrst(struct powerdomain *pwrdm, u8 pwrst);
 int pwrdm_read_next_pwrst(struct powerdomain *pwrdm);
+int pwrdm_read_pwrst(struct powerdomain *pwrdm);
 int pwrdm_read_prev_pwrst(struct powerdomain *pwrdm);
 int pwrdm_clear_all_prev_pwrst(struct powerdomain *pwrdm);