regulator: add regulator_can_change_voltage stub
regulator: add regulator_can_change_voltage stub

When CONFIG_REGULATOR is not set, we cannot call
regulator_can_change_voltage() from a device driver, which results
in a build error like

video/fbdev/omap2/dss/hdmi5.c: In function 'hdmi_init_regulator':
video/fbdev/omap2/dss/hdmi5.c:149:2: error: implicit declaration of function 'regulator_can_change_voltage' [-Werror=implicit-function-declaration]

even for drivers that don't require the regulator API normally.
Such a use was recently added in the omap2+ hdmi driver.

This avoids the problem by adding a static inline function
stub in the API header, as we have for most of the other
regulator functions as well.

Signed-off-by: Arnd Bergmann <f2c659f01951776204a6c5b902787d9019fbeebd@arndb.de>
Cc: Mark Brown <b51b9a92386687a9ac927cebfa0f978adeb8cea5@kernel.org>
Cc: Tomi Valkeinen <e1ca4dbb8be1acaf20734fecd2da10ed1d46a9bb@ti.com>
Signed-off-by: Mark Brown <b51b9a92386687a9ac927cebfa0f978adeb8cea5@linaro.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs