ARM: OMAP: Fix reprogramming of dpll1 rate

Commit a66cb3454f220f49f900646ebdc76cb943319eb7 (ARM: OMAP: Map SRAM
later on with ioremap_exec()) moved the SRAM init to happen later
to remove a dependency to early SoC detection for map_io.

This broke booting on some boards not using Kconfig option for
OMAP_CLOCKS_SET_BY_BOOTLOADER as the dpll1 reprogramming would
cause the following error:

kernel BUG at arch/arm/plat-omap/sram.c:226!
Internal error: Oops - undefined instruction: 0 [#1] PREEMPT
Modules linked in:

CPU: 0    Not tainted  (3.2.0-rc1-e3 #9)
PC is at omap_sram_reprogram_clock+0x28/0x30
LR is at omap1_select_table_rate+0x88/0xb4
pc : [<c001b0c4>]    lr : [<c0019f54>]    psr: 600000d3
sp : c035bf10  ip : c035bf20  fp : c035bf1c
r10: c035bfd4  r9 : 54029252  r8 : c03f8120
r7 : c0362b50  r6 : 00b71b00  r5 : c03873cc  r4 : c0362b40
r3 : 00000000  r2 : c0362b40  r1 : 0000010a  r0 : 00002cb0
Flags: nZCv  IRQs off  FIQs off  Mode SVC_32  ISA ARM  Segment kernel
Control: 0000317f  Table: 10004000  DAC: 00000017
Process swapper (pid: 0, stack limit = 0xc035a270)
Stack: (0xc035bf10 to 0xc035c000)
bf00:                                     c035bf3c c035bf20 c0019f54 c001b0ac
bf20: 00001000 00002cb3 00000004 c035ed4c c035bf74 c035bf40 c033ea24 c0019edc
bf40: c02f526c 00000002 00000015 bc058c9b 93111a16 c035335c 02000000 c035ed4c
bf60: c035ed4c c03f8120 c035bf84 c035bf78 c00194c4 c033e8ec c035bfc4 c035bf88
bf80: c033bc24 c00194a0 c035bf90 c035bf98 00000000 00000000 00000000 00000000
bfa0: 00000001 00000000 c0354678 c035ece4 10004000 103532f4 c035bff4 c035bfc8
bfc0: c0338574 c033b598 00000000 00000000 00000000 c035467c 0000317d c035c03c
bfe0: c0354678 c035ece4 00000000 c035bff8 10008040 c0338508 00000000 00000000
Backtrace:
[<c001b09c>] (omap_sram_reprogram_clock+0x0/0x30) from [<c0019f54>] (omap1_select_table_rate+0x88/0xb4)
[<c0019ecc>] (omap1_select_table_rate+0x0/0xb4) from [<c033ea24>] (omap1_clk_init+0x148/0x334)
 r7:c035ed4c r6:00000004 r5:00002cb3 r4:00001000
[<c033e8dc>] (omap1_clk_init+0x0/0x334) from [<c00194c4>] (omap1_init_early+0x34/0x48)
 r8:c03f8120 r7:c035ed4c r6:c035ed4c r5:02000000 r4:c035335c
[<c0019490>] (omap1_init_early+0x0/0x48) from [<c033bc24>] (setup_arch+0x69c/0x79c)
[<c033b588>] (setup_arch+0x0/0x79c) from [<c0338574>] (start_kernel+0x7c/0x2f4)
[<c03384f8>] (start_kernel+0x0/0x2f4) from [<10008040>] (0x10008040)
 r7:c035ece4 r6:c0354678 r5:c035c03c r4:0000317d
Code: 0a000002 e1a0e00f e12fff13 e89da800 (e7f001f2)

Fix this by adding omap1_clk_late_init() that only reprograms dpll1
if the bootloader rate is less than 60MHz. This also allows removing
of the OMAP_CLOCKS_SET_BY_BOOTLOADER option.

Reported-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Tested-by: Aaro Koskinen <aaro.koskinen@iki.fi>
Signed-off-by: Tony Lindgren <tony@atomide.com>