SPEAr : Adding README.spear in doc

README.spear contains information about SPEAr architecture and build options etc

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+SPEAr (Structured Processor Enhanced Architecture).
+
+SPEAr600 is also known as SPEArPlus and SPEAr300 is also known as SPEArBasic
+
+The SPEAr SoC family also embeds a customizable logic that could be programmed

Could be changed to
"The SPEAr SoC family embeds customizable logic that can be programmed"

+one-time by a customer at silicon mask level (i.e. not at runtime!).

+We are now adding the support in u-boot for two SoC: SPEAr600 and SPEAr3xx.

This could be moved to 2nd sentence.

+Pls note that SPEAr300/310/320 differs only for the default customization.

This is not needed.

+
+All 4 SoCs share common peripherals.
+
+1. ARM926ejs core based (sp600 has two cores, the 2nd handled only in Linux) +2. FastEthernet (sp600 has Gbit version, but same controller - GMAC) +3. USB Host
+4. USB Device
+5. NAND controller (FSMC)
+6. Serial NOR ctrl
+7. I2C
+8. SPI
+9. CLCD
+10. others ..
+
+sp600 is not customized by default.
+sp3xx are differently customized.

Please explain what you mean by customizing and differently customizing

+sp300 is more oriented to TELECOM/video (it has tdm, i2s, ITU i/f support) +sp310 for networking (a part GMAC in fixed part, it has 5 MACB ctrls in +custom)
+sp320 for industrial (SPP ctrl, CAN ctrl, 2 MACBs, ...)
+
+Everything is supported in Linux.
+u-boot is not currently supporting all peripeharls (just a few). +
Please list what is supported.

+More description can be found on Internet, for example here:
+ +http://embedded-system.net/spear-basic-customizable-arm-based-soc-stmicroelectronics.html

This is press release and will likely be short lived. Please change this to something from www.st.com

Tom