ARM: OMAP: replace custom sr32() by standard I/O accessors

Replace the custom bit manipulation function sr32() by standard I/O
accessors.  A major motivation for this cleanup was the fact, that a
number of calls of that function resulted in 32 bit wide shift
operations on u32 data, which according to the C-ISO/IEC-9899-Standard
provokes undefined behaviour:

	6.5.7 Bitwise shift operators
	...
        If the value of the right operand is negative or is greater
        than or equal to the width of the promoted left operand, the
        behavior is undefined.

Signed-off-by: Wolfgang Denk <wd@denx.de>
Cc: Tom Rini <trini@ti.com>
Cc: Albert ARIBAUD <albert.u.boot@aribaud.net>