bus: omap_l3_noc: Add information about the context of operation

L3 error may be triggered using Debug interface (example JTAG) or
due to other errors, for example an opcode fetch (due to function
pointer or stack corruption) or a data access (due to some other
failure). NOC registers contain additional information to help aid
debug information.

With this, we can enhance the error information to more detailed form:
"
L3 Custom Error: MASTER MPU TARGET L4PER2 (Read): Data Access in User mode
during Functional access
"

Signed-off-by: Nishanth Menon <nm@ti.com>
Acked-by: Santosh Shilimkar <santosh.shilimkar@ti.com>
Acked-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Tested-by: Darren Etheridge <detheridge@ti.com>
Tested-by: Sekhar Nori <nsekhar@ti.com>