Input: remove dead CSR Prima2 PWRC driver

Commit f3a73284 ("ARM: remove sirf prima2/atlas platforms") removes
the config ARCH_SIRF in ./arch/arm/mach-prima2/Kconfig.

Hence, since then, the corresponding CSR Prima2 PWRC Driver is dead code.
Remove this dead driver.

Signed-off-by: Lukas Bulwahn <lukas.bulwahn@gmail.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Link: https://lore.kernel.org/r/20210817072842.8640-1-lukas.bulwahn@gmail.com


Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>