staging/easycap: reduce code duplication for ssa stk settings

reduce code duplication in register settings

instead of
	if (ntsc)
		<CODE BLOCK>
	else
		<CODE BLOCK>
use

	cfg = (ntsc) ? <chip>configNTSC : <chip>configPAL;
	<CODE BLOCK>

in addition change while loops to more readable for loops

Cc: Mike Thomas <rmthomas@sciolus.org>
Signed-off-by: Tomas Winkler <tomas.winkler@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>