mmc: msm: fix up build breakage on !PM

with PM disabled I get the following compile error,

drivers/built-in.o: In function `msmsdcc_resume':
linux-2.6/drivers/mmc/host/msm_sdcc.c:1352: undefined reference to `mmc_resume_host'
drivers/built-in.o: In function `msmsdcc_suspend':
linux-2.6/drivers/mmc/host/msm_sdcc.c:1330: undefined reference to `mmc_suspend_host'

This adds ifdefs around the suspend/resume functions to prevent this.

Signed-off-by: Daniel Walker <dwalker@codeaurora.org>