ahci_imx: depend on CONFIG_MFD_SYSCON
ahci_imx: depend on CONFIG_MFD_SYSCON

ahci_imx makes use of regmap but the dependency wasn't specified in
Kconfig leading build failures if CONFIG_AHCI_IMX is enabled but
CONFIG_MFD_SYSCON is not.  Add the Kconfig dependency.

Signed-off-by: Tejun Heo <546b05909706652891a87f7bfe385ae147f61f91@kernel.org>
Reported-by: Stephen Rothwell <4bf0fb350827ce8d86875e76c923a478597c3cef@canb.auug.org.au>

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