power: pm8921-charger: Add delay after turning on D0 (TCXO) clock

On APQ8064, TCXO cannot be turned off before its warm-up period (4ms).
This is not required on the platform which have a CXO. Add a warm-up
delay after turning on D0 (which turns on the TCXO).

Signed-off-by: Anirudh Ghayal <aghayal@codeaurora.org>

Conflicts:
	arch/arm/mach-msm/board-8064-pmic.c
	drivers/power/pm8921-charger.c
	include/linux/mfd/pm8xxx/pm8921-charger.h

Change-Id: Iaa91b8051d6d6ed7bd6394cc920411792b176224

Conflicts:

	drivers/power/pm8921-charger.c
power: pm8921-charger: Add delay after turning on D0 (TCXO) clock