The PXA platform has a number of configurations that end up with
a warning like these when building with W=1:

drivers/hwmon/max1111.c:83:5: error: no previous prototype for 'max1111_read_channel' [-Werror=missing-prototypes]
arch/arm/mach-pxa/reset.c:86:6: error: no previous prototype for 'pxa_restart' [-Werror=missing-prototypes]
arch/arm/mach-pxa/mfp-pxa2xx.c:254:5: error: no previous prototype for 'keypad_set_wake' [-Werror=missing-prototypes]
drivers/clk/pxa/clk-pxa25x.c:70:14: error: no previous prototype for 'pxa25x_get_clk_frequency_khz' [-Werror=missing-prototypes]
drivers/clk/pxa/clk-pxa25x.c:325:12: error: no previous prototype for 'pxa25x_clocks_init' [-Werror=missing-prototypes]
drivers/clk/pxa/clk-pxa27x.c:74:14: error: no previous prototype for 'pxa27x_get_clk_frequency_khz' [-Werror=missing-prototypes]
drivers/clk/pxa/clk-pxa27x.c:102:6: error: no previous prototype for 'pxa27x_is_ppll_disabled' [-Werror=missing-prototypes]
drivers/clk/pxa/clk-pxa27x.c:470:12: error: no previous prototype for 'pxa27x_clocks_init' [-Werror=missing-prototypes]
arch/arm/mach-pxa/pxa27x.c:44:6: error: no previous prototype for 'pxa27x_clear_otgph' [-Werror=missing-prototypes]
arch/arm/mach-pxa/pxa27x.c:58:6: error: no previous prototype for 'pxa27x_configure_ac97reset' [-Werror=missing-prototypes]
arch/arm/mach-pxa/spitz_pm.c:170:15: error: no previous prototype for 'spitzpm_read_devdata' [-Werror=missing-prototypes]

The problem is that there is a declaration for each of these, but
it's only seen by the caller and not the callee. Moving these
into appropriate header files ensures that both use the same
calling conventions and it avoids the warnings.
Acked-by: Stephen Boyd <sboyd@kernel.org>
Link: https://lore.kernel.org/r/20230516153109.514251-11-arnd@kernel.orgSigned-off-by: Arnd Bergmann <arnd@arndb.de>