OMAP2+ powerdomains/clockdomains: prepare for multi-OMAP configs

Convert CONFIG_ARCH_OMAP34XX to CONFIG_ARCH_OMAP3, and
CONFIG_ARCH_OMAP24XX to CONFIG_ARCH_OMAP2, in preparation for Tony's
multi-OMAP patches.

While here, update some copyrights, convert instances of "34xx" to
"3xxx" where applicable, and convert preprocessor directives of the
form

    #if defined(CONFIG_ARCH_OMAP2) | defined(CONFIG_ARCH_OMAP3)

to

    #if defined(CONFIG_ARCH_OMAP2) || defined(CONFIG_ARCH_OMAP3)

for standardization.

Signed-off-by: Paul Walmsley <paul@pwsan.com>
Cc: Tony Lindgren <tony@atomide.com>