ARM: dts: dra72-evm: Fix spurious card insert/removal interrupt

ldo1_reg in addition to being connected to the io lines is also
connected to the card detect line. On card removal, omap_hsmmc
driver does a regulator_disable causing card detect line to be
pulled down. This raises a card insertion interrupt and once the
MMC core detects there is no card inserted, it does a
regulator disable which again raises a card insertion interrupt.
This happens in a loop causing infinite MMC interrupts.

Fix it by making ldo1_reg as always_on.

Signed-off-by: Kishon Vijay Abraham I <kishon@ti.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>