ARM: OMAP2+: hwmod: Fix a crash in _setup_reset() with DEBUG_LL

With commit '82702ea1

' "ARM: OMAP2+:
Fix serial init for device tree based booting" stubbing out
omap_serial_early_init() for Device tree based booting, there was a
crash observed on AM335x based devices when hwmod does a
_setup_reset() early at boot.

This was rootcaused to hwmod trying to reset console uart while
earlycon was using it.  The way to tell hwmod not to do this is to
specify the HWMOD_INIT_NO_RESET flag, which were infact set by the
omap_serial_early_init() function by parsing the cmdline to identify
the console device.

Parsing the cmdline to identify the uart used by earlycon itself seems
broken as there is nothing preventing earlycon to use a different one.

This patch, instead, attempts to populate the requiste flags for hwmod
based on the CONFIG_DEBUG_OMAPxUARTy FLAGS. This gets rid of the need
for cmdline parsing in the DT as well as non-DT cases to identify the
uart used by earlycon.

Signed-off-by: Rajendra Nayak <rnayak@ti.com>
Reported-by: Mark Jackson <mpfj-list@newflow.co.uk>
Reported-by: Vaibhav Bedia <vaibhav.bedia@ti.com>
Tested-by: Mark Jackson <mpfj-list@newflow.co.uk>
Signed-off-by: Paul Walmsley <paul@pwsan.com>