Ensure read and write of flags are 32 bit

Ensure read and write of flags are 32 bit

In 'console_set_scope' and when registering a console, field 'flags' of
'console_t' is assigned a 32-bit value. However, when it is actually
used, the functions perform 64-bit reads to access its value. This patch
changes all 64-bit reads to 32-bit reads.

Change-Id: I181349371409e60065335f078857946fa3c32dc1
Signed-off-by: Daniel Boulby <daniel.boulby@arm.com>