ARM: OMAP4+: PRM: add support for passing status register/bit info to reset

AM43xx has slightly different reset register layout compared to OMAP4+,
with varying status bit shifts and status register offsets. Current
code assumes static offsets and identical status / reset control bit
shifts, which is wrong. This patch adds PRM core support for passing
the actual implementations from hwmod code. AM43xx mappings will be fixed
in subsequent patch.

Signed-off-by: Tero Kristo <t-kristo@ti.com>
Reported-by: Dave Gerlach <d-gerlach@ti.com>
Reported-by: Suman Anna <s-anna@ti.com>
Signed-off-by: Paul Walmsley <paul@pwsan.com>