mmc: rtsx_pci_sdmmc: increase power-on settling delay to 5ms

mmc: rtsx_pci_sdmmc: increase power-on settling delay to 5ms

The existing 1ms delay in sd_power_on is insufficient and causes resume
errors around 4% of the time.

Increasing the delay to 5ms resolves this issue after testing 300
s2idle cycles.

Fixes: 1f311c94aabd ("mmc: rtsx: add 74 Clocks in power on flow")
Signed-off-by: Matthew Schwartz <matthew.schwartz@linux.dev>
Link: https://patch.msgid.link/20260105060236.400366-3-matthew.schwartz@linux.dev
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>